Hi Lela,
I've just been musing a bit, but these are rather random thoughts, so feel free to roll your eyes at me:
One thing that will happen when the baby is born is that everyone will know it's a boy - this pressure of keeping your secret and feeling bad about it will be gone as soon as the baby is born. That might be something that helps - you can release some of the feelings of guilt and stress.
With a nappy on, all babies look very similar - obv, I know, but bear with me. Try to focus on what your baby's face will look like, and wee hands with tiny fingernails, little rosebud mouth, seashell eyes, etc. When ds was born he was like a smaller version of dd - they were so alike it amazed me, and I just remember stroking his tiny tiny hand, and just marvelling at the size of it. Just take the time to look at his face, his hands, his feet, and get to know him as a person, rather than A Boy, if you see what I mean.
Newborns often look like their fathers, I think, and so try to think about what your dp was like when he was little. You love him - maybe ask him for happy stories about when he was small - he'll enjoy telling them, and it may help create a better image of what this new person - not boy or girl, just new person, mixture of the pair of you - will be like.
It may be harder for your friend to know what to do than us - we only know you through this thread, and although you are patently a very likeable person, wwe've got no preconceptions of you to break down before accepting where you are now - that's much more difficult to do with RL friends. hard to say, but give her time, and blurt out to us.
One of the things I find annoying now I have a boy is the presumptions that people make about him - he's a shocking sleeper, god love him, and people all say "oh, it's because he's a boy" - which is such unbelievable nonsense - dd wasn't great for ages, and no-one had a gender-related comment for that. I was a terrible sleeper too, which is more likely the cause! My sister's two girls are much less alike than my ds and dd, and yet ds's characteristics, even those just like dd's, are ascribed to his gender.
Boys get tarred unfairly, I think, and since dd has been to playgroup, I've really reasssessed my ideas about boys - the 3 yos are so sweet and gentle, it's amazed me. They come up to ds and give him things, and stroke him - the girls are often much more rough!
I know that you aren't being silly aabout this, that the thoughts you have come unbidden, but I thought that just telling you my experiences might help give you a little bit of positivity to fix upon from time to time.
Why do you have to come off medication before the birth? How long beforehand will you have to stop? Some of the physical tiredness will absolutely be pregnancy-related, and that will ease. See if you can get your freezer filled up - maybe dp can help? - with food over the next few weeks, so there's always something handy to eat.
Names are tricky, partic. names for boys. what kind of names do you like? We may be able to come up with ones you haven't considered.