I used to be a total top because I couldn't handle being penetrated. I eventually learned how to enjoy bottomimg and now I mostly bottom. I still would like to top but I'm not hung and a lot of bottoms prefer big dicks. What I've learned along the way is that bottoming doesn't have to hurt (take your time to relax and use lots of lube and often), you can take charge of your own pleasure even as a bottom (make what your feeling known and take controlnof the positions), it's 50% psychological and 50% sensation (for me) -- I personally don't derive the same pleasure having a dildo in me the same as looking a guy in the eye while getting fucked or seeing myself get fucked in the mirror.