Big virtual hugs. Please accept my deepest condolences for losing your baby.
After everything you've gone through, you sound exhausted with the whole thing including the grief.
I haven't 'been there' so I'm sorry I can't offer you that understanding but I care that you feel you're going through this alone, so wanted to offer some comfort, if that's possible.
I've supported young people confused about their sexuality, all have now told their parents and have been loved through this. It brings me so much joy to see them living their truth! Their happiness is tangible (ok except for the usual heartbreaks etc). I have a few friends who've left their husbands because they couldn't stay. They're all happy they left and sought same sex relationships, just saying this but I'm still not qualified!
I would really love to hear that you have found a counsellor to talk through your feelings. One that specialises in gender and sexuality would be best IMHO. There are also helplines and I hope you can access some support because LOTS of people go through this. You're not alone but I know you feel that way atm. Hugs.
I'm actually quite heartened that you're acknowledging things about yourself that you haven't wanted to before. You may not want to now, but I guess it could be like fighting the tides?
Have you watched or read much of Stephen Fry? I love him! He once described what hetero people maybe didn't know.... that some people are only a % gay. He described himself as in the 90s% gay, not bi. It would be non PC giving my own thoughts, I rely on people who are, to help me understand things.
I don't think you have to cause premature issues in your marriage by openly discussing things with H yet. I think you need the clarity of mind first, which may come with a counsellor's support, then to make a decision and then have the discussion, if you need to.
Once your decision is made, no amount of talking could change your mind. Ofcourse your H will go through things about it all, and I hate to say this, but he is not your responsibility really. I will go so far to say that if your feelings increase so much for the other sex, then releasing him to find someone would be the best thing for his happiness in the long term.
It's not like you haven't tried.