TinyMackBear4 YANBU, you are totally entitled to feel how you do about the proposal.
You were not happy. And the fact it still affects after all this time may well mean you need to address it.
However, I think I can see a few reasons why you would feel like that.
The engagement came hot on the heels of your miscarriage. Maybe your fiance felt proposing then would help, would reassure you of his love etc.
Did it reassure you of his love?
Other people not being bothered how their proposals went isn't really relevant OP, it's how you feel about your proposal that counts for you. That's not to say you cannot change how you feel, if you genuinely feel differently after reading other people's stories, great.
You've got a new baby, may well be suffering from some post natal depression or baby blues - and you may also be remembering the grief you felt in loosing your baby last year.
The people asking you (or rather telling you) to get a grip, need to get one themselves! IMHO.
So I'd think your first job is to get better if you really do have a touch of the baby blues. Come to terms with the fact your first baby did not get to be born (if you are still upset by this, maybe you are not, but I can't help but think the engagement reminds you of this).
If you would benefit from a bit of counselling, get some, please and move on.
Your finance knows the way he asked you was not great, can you talk about it when you are more 'recovered' from the birth?
Can you discuss the proposal at some point and either move on or recreate it together how you wanted it to be? If this idea sounds naff, ignore.
Then, when you are ready, concentrate on your wedding and the continuation of your lives together.
You are neither entitled nor in need of a grip, but rather in need of some TLC, I hope your fiance will be able to supply it, with love and care and your future together will be beautiful and bring.
Move on with style.
XXX 