I’m exactly the same as you! However I think it can’t be helped. Even if I skip the afternoon nap I still can’t seem to fall asleep at night. It can be worse in the 3rd trimester because if baby’s sleep cycle is different from you sometimes he/ she may kick while you’re trying to sleep which makes things even worse. I had some form of insomnia relief during the 1st trimester when blocked/runny nose was one of my pregnancy symptoms and the doctor prescribed drowsy meds for me. That was the only time I could properly sleep. But it went away after 12 weeks so right now I’m back to square and suffering insomnia. Spoke to my gynae about this, she said it actually doesn’t affect the baby. But due to lack of sleep many things can happen such as losing balance/ falling over etc so we need to be abit more careful.
It is normal for pregnancy mummy to have insomnia. I had it for my second pregnancy but not my first. I watch netflix, youtube, drink warm chocolate drink/tea, toss turn until I fall asleep. Nothing can be done because most mummies had it. Otherwise, I suggest you don't have afternoon nap, and it will help you sleep better at night when you are tired.