I just cant feel pion for him. WHY?

love my BF, i'm very attracted to him, we communicate & get along great, our relationship is awesome, is awesome, we're "in love" but we dont MAKE LOVE. i have the hardest time feeling PION for him. the times i did, was 2 or 3 times & also when we went to the movies we got into serious kissing sessions & my pion was at a high & his response was even better, which made MINE more intense. 99% of the time i'm not feeling that pion & i dont know why & i dont know what to do about it. its bothering us - he's upset (we talked about it). we've had alot of serious arguments, we live together, never went thru a real courtship, both have insecurities, i question secretly if we're meant to be together & imagine him with another chick all the time, we both have trust issues, both jealous & possessive & both hot-headed. seems like every few days we're arguing. but we make up, talk things out & when we're not arguing things are so beautiful. we really want to be together. we agreed to go to therapy sessions but i'm wondering if that's going to help. my main concern right now is why i dont feel pion for him & what to do about it?? any suggestions please? we really want to be together.