I believe some sexual acts have "learned" components, especially when they relate to other people. I suspect since you have abuse issues you have to practice and learn to get comfortable in new ways? Too, could be it takes a certain someone, etc.
The sexual portion is "built in" and that you achiee orgasm at all means you have all the right "parts" and they work? I was cheered when I was younger and thought there was something wrong with me to realize that and understand the rest is just behavior/learning/emotional stuff.