You save your relationship by first trying to express your feelings to your boyfriend. The feelings, if you feel them, that you really like him and want to make a future with him. That your scared, hurting, and lost without not really knowing what to do to help yourself. You admit you know you have problems and profess your earnest desire to change even though you don't know how but you express your desire to learn. And you ask him to be there for you and profess your thanks for his support. The rest is up to him. From there the best option is professional therapy. Start working through everything that happened and the current damaging effects it's having on your feelings, ability to feel, life skills and especially relationship skills. Problems such as the ones you have identified. Why is the effect there? What are the feelings/thoughts behind it? What are the feelings towards the incident and alot of things in your life. Explore feelings deeper to get at the core ones then identify sources, diffuse sources, change them, and start promoting different feelings in yourself. A similar process applies for behaviors or getting to the core reason for the behavior, diffusing it, and changing it to start promoting better behaviors and resisting this one. Dealing with any attractions or connections you have to undesired behaviors. So alot of it is on you; where would you like to start? Just pick the most damaging thing to your life or relationship and start there. There's no magic solution to make it all disappear. No magic solution to fix every problem as every problem requires exploration and a different and unique solution. Just take it a step at a time and start moving forward.
If you feel like it's too early to start addressing your problems then just began exploring them by talking about it all. With your boyfriend, a therapist, on here, or with yourself. Just get that exploration going to bring out feelings and thoughts. And to bring it all into perspective. So please, if it would help feel free to talk about whatever is on your mind.