I'll start by saying that this is very puzzling.
............
Not this bit, but what you have been told by your H.
My misgivings are more that it is very ‘other’ to start to consider the presence of religion in my direct family life. I have embedded negative feelings towards faith in general because of my childhood which I recognise won’t necessarily come true but are still there nonetheless. I worry that there will be an expectation there for me to become more involved and I don’t know now if that is what I want. Or what I want for our children. And I think all these things should be clearer before commitments are made by my husband.
I definitely think a cooling off period should happen. There is no rush (in my mind) and if he feels the same way in a years time then he could consider it again then. I don’t know how he will feel about that as had no chance to discuss it yet.
And I think i am worried that it’s not the right path for him too - personally I know how swayed I can feel when involved in the ritual towards the more spiritual and he is more involved with it than ever currently with the course etc.
Your H thinks this decision he has made to be baptised is a personal thing, and you say you agree, but you shouldn't agree. I am saying this as a practicing Catholic. There is a little high handedness going on here, and I wonder why you have been excluded so far from the process, if there is a process, that your H is taking part in. It is very late in the day to sit down and talk about the children and the impact on your relationship of all of this. This should have been done a long time ago.
You most certainly should have a chat with the priest. Please don't do this on a casual basis. Make an appointment and send your questions ahead of you in an email or letter. But first sit your H down and ask him if he is involved in RCIA or what sort of process of discernment and preparation he is on, what programme, who runs it...
I am very surprised that you have not spoken to the priest earlier. This would be most unusual where I am (RC parish in the US where numerous adult baptisms and confirmations take place every year, plus numerous older child baptisms).
What if the kids all become catholic and I’m left out? What if it’s just him who stays that way and he therefore becomes more distance from us?
The reverse took place in my dad's family, with RC parents gradually realising that their children were nearly all Buddhists... Takes all sorts.
Seriously though, you need to talk to the priest about this and so much else, and again, I am very surprised indeed that none of this has been discussed up to now.
Things you need to ask about:
The marriage blessing - necessary? Your reservations.
Impact on your marriage and your family life of a newly active belief system and possibly new observances on the part of your H.
Children to be Catholic?
Please, please talk about your hangups and negative experiences as a child. Your parents' relationship.
...the bind to church and its community being all encompassing and restrictive. This perception too.
Lent is just around the corner - beginning on Valentine's Day this year (aka Ash Wednesday) followed by Easter in 7 weeks. So about nine weeks away. Easter is seven weeks after that.
If your H is in RCIA then he is on the home straight at this point. What he will not have is any sort of a cooling off period available at this point unless he wants to put it off and be baptised/confirmed at a later date.
I am concerned that you do not seem to be in the loop here even to the extent of not knowing about the Saturday vigil Mass, and that your H may have been involved in RCIA for at least several months now, perhaps a whole year (I may be barking up the wrong tree here completely however), that you have important questions that have not been answered, and again (I keep on coming back to this) - no contact with the priest and no reaching out from him.
Were you planning to go to the baptism/confirmation?
In my parish, the baptism or confirmation (often both together) is attended by families, many of whom are not RC at all, but they are there in reserved pews and seem happy. The priests involved have always taken a lot of time at the Mass to talk about the families and the backgrounds of those being baptised or confirmed and to thank families for laying a foundation of faith or encouraging the inquiring minds of their family members. With this in mind, your H's contention that baptism is a personal and private matter seems very odd indeed.
The process in the diocese of Glasgow looks very similar to the process in my parish:
www.rcagliturgy.org.uk/interested-in-becoming-a-member-of-the-catholic-church.html
What is the process of the RCIA?
<span class="italic">Period of Evangelisation and Pre-catechumenate</span>
This is a time of no fixed duration where the seeker or inquirer has the opportunity to be opened to the values of the Gospel and the beginning of the journey of faith.
First Step: Acceptance into the Order of Catechumens
This is the first public step taken by the seeker and marks the beginning of the period of the catechumenate and acceptance of the seeker by the Church and indeed the worshipping community.
<span class="italic">Period of the Catechumenate:</span>
During this period, the faith and growth of the catechumen is nurtured and strengthened. This is enhanced by celebrations of the Word of God and prayers of blessing.
<span class="italic">Second Step: Election or enrolment of names</span>
This rite is celebrated in the Cathedral every year of the First Sunday of Lent. For the first time, all those seeking initiation into the Church community from each parish in the Archdiocese come together. It is during this celebration that the catechumens and candidates are declared "elect" to receive and share in the sacramental life of the Church.
<span class="italic">Period of Purification and enlightenment</span>
During the season of Lent, the elect are called to deeper reflection and conversion in preparation for the celebration of the Sacraments at the Easter Vigil. This is helped by the celebration of "scrutinies" and presentations with the Creed and the Lord's Prayer.
<span class="italic">Celebration of the Sacraments of Initiation</span>
The Easter Vigil is the highlight of the Church's year, and it is normally at this celebration that the Christian Initiation of Adults take place. Those who have been elected are initiated into the Church by Baptism, Confirmation and Eucharist.
<span class="italic">Mystagogy</span>
The time following Christian Initation is a time of celebration for the newly baptised and initiated into the Church and also a time for them to adapt to their new role within the community of the Church. This stage in the journey is normally concluded with a diocesan celebration of the great feast of Pentecost.
Sorry to include this if your H is not in fact involved in the RCIA process. It's not clear from your posts if he is or not:
(1) My husband, as part of his professional development, has been attending a catholic course which should you so wish, at the end, you can choose to convert/become a catholic and go through the necessary events to do so. He has come home today and said he thinks he would like to do that.
(2) -he is doing the course that people do to convert and should convert at Easter vigil this year should he choose to.
Some points:
(1) RCIA would not be part of professional development. The decision to be baptised/confirmed is supposed to be completely voluntary and the process of discernment and commitment takes place outside of any professional context.
(2) He would have been in RCIA for about a year now, with all of the above participation in rites for catechumens at Mass, small group study and possibly a retreat or two, if he is going to be fully received into the Church at Easter this year, which is 16 weeks away.
Are you aware of any of the activities and preparations I C&Pd on his part?
Again, heartfelt apologies if I have got the wrong end of the stick.