Flowers,
I'm more of a lurker than a poster , so you will not know me.
What your partner needs to realise is that's it shouldn't be about you 'fixing yourself' or airing his assumptions on what type of rubbish parent you would make.
What it should be about is him showing some support and understanding to his partner right now - at a time when you need it most.
Lets face it - he's not showing himself to be up to the job of being a perfect parent and role model to his future children now, why would he suddenly change if they arrived.
Children are for life, are demanding,rewarding, draining ,enlightening little beings all with characters of their own and not all of them are easy.
He is showing himself as having little staying power (already on dating sites) , idealistic ( time to move on ), and power trippy ( knocking you further down with his views on your failings )
He needs to step up.
Become compassionate to your feelings, not thwart them.
Stop labelling you and look at himself.
Support you through a hugely tough time.
And then some more.
Many condolences on loosing your Mum, 3 months is all so soon and fresh.
I lost my Mum and was a ' mess' for a long time. My kids were what helped me to get out of bed in the mornings, I am sure I wasn't a perfect parent at that time - but then I don't think anyone expected me to be or stood judging me; I felt a lot of acknowledgement and support for my grief though.
I cannot believe he could say to you 'imagine what you would be like if you lost your Dad too' .
That's plain cruel .
It happened to me though , I lost my Dad too fairly recently.
It's horrible, but again I have been allowed to grieve as I have needed too.
The thing with grief - if you hold in in; it at least doubles.
All of your 'problems' are not 'yours' , they are his - he has much more sorting himself out than you do.
What you have is natural feelings and reactions to loosing a parent , why you should be made to feel guilty and inferior for that ? No right answer for it.
Look after yourself - he isn't.