I'm so alone & unhappy:(

I am 23 yrs old, my boyfriend & i have been together for just over 3 years. we have a 2 yr old daughter and live together. we've had our ups and downs. mostly downs, but somehow managed to stick together and were doing fine until recently. i feel so alone and don't kow what to do to fix things. i just feel like giving up and throwing in the towel, and then i think about my daughter and how she deserves a shot at the normal happy family i never had. My boyfriend and i fight constantly, he doesn't trust me at all and is always accusing me of cheating or lying or something i'm doing wrong. he says everything that is wrong with our relationship is my fault. i admit my faults most of the time, but there is no way EVERYTHING can be my fault. that's not the case in ANY relationship. even the thought of me having guy friends angers him off. he automatically thinks i like them or they like me. i just don't know what to do. its constant. we end up fighting and getting into huge arguments and there is so much tension in our home. then over time we get better and he agrees to stop and i agree to try harder to think of his feelings and we are ok for a few days, or weeks, then all of a sudden he decides he wants to be pissed about what we already settled and discussed during our last argument. i am just so unhappy and feel like a child. he makes me feel like i'm not allowed to do anything or go anywhere without him giving me a guilt trip or having to hear him accuse me of crazy stuff when i get home. i feel like there are so many things wrong with our relationship i can barely think of any good things about it.
a part of me feels like just giving up and breaking up so bad and dealing with the hard times and adjustments of being a single mom ad having to share my daughter with him, but the other part of me loves him so much and wants to try so hard to make it work. i just do't ever see it changing. i just really need someone to talk to right ow. i'm so alone:(