I love him but im at a loss..?

I love him alot and hes kind of sweet towards me. We have gone through for about 2plus years, going on to 3. But some things happened which really made my trust for him waver.. And some of the more serious incidents really hurt me alot. Till now, im kind of afraid of him. I dont really dare to start the conversation etc etc. And i even find myself doubting him and being wary of him. I guess its cos i was really hurt quite badly that time. I dont know how we manage to get through these years, seriously. I really love him but im afraid that if this goes on, i will have to go through the pain and sufferings all over again.. What should i do? I really dont know. Everytime i tell myself i must move on, just a sms from him would cancel off all my efforts. I dont know why i just keep going back to him! What should i do?