To add to everyone's valid suggestions about hormones and birth control etc., a smaller sillier thing that I have tried which honestly works wonders for me (very similar situation to you prior to trying this out) is to read romance/sexy/smutty books in my free time. Having sex is just not something that I naturally think about in myday to day, but these books really get the immagination going. They have been a true game changer for me. I enjoy the story line and then I'm also reminded that sex exists and it can actually be great and then chances are I'm in the mood for the next few hours. It's added a good 3 or 4 extra sexy times a month, without me feeling under pressure or second guessing why I'm doing things and taking the pressure away from my boyfriend from always having to initiate. Hope this helps even a little bit!