When I try dating someone I become depressed.

I think at times that I am the only person this happens to but I still want to reach out for help. I'm in my twenty's and have not been in a serious relationship since I was in high school. I had dated a guy for a year then dated another gentlemen for 2 years but my senior year I broke up with him because I was overwhelmed with my parents divorce and my fathers infidelity. 2 years later I have dated 1 guy for a month and it was the worst month. I was so depressed I couldn't sleep. I was so afraid he didn't like me or i did something wrong when nothing even happened. Now 2 years after that relationship I have seen a pattern that I do. When Im not talking with someone I'm sad because I think I will never be with someone but then when I find someone and start talking to them I get very excited because I do want a boyfriend and I do want to be happy but I will make myself so upset by the littlest things. If he says he is going to call I will worry the whole time on if he is or if he isn't instead of just waiting to see if he is going to call. I'm afraid that he is talking to other people ( even if we have been talking for 2 weeks). I dont let things happen I try to make things happen to protect myself from getting hurt but in the end I'm hurting myself more because I constantly worry if he likes me, is this going anywhere, is there another girl? Its like I o most become obsessed just to try and keep myself from being hurt. I cant seem to let a guy in for these reasons. Even when I do let a guy in just a little im so insecure that I'm afraid I will push him away because i instantly want to know where things are going, and I will question him on if he wants to date me or just think he is going to get sex from me. Even when they tell me their awnser like "i just want to take things slow I just got out of a long term relationship" Its not the awnser I want to her I want to hear " I like you and yes I can see myself dating you" So i will take the awnser he gave me and think of all these bad possibilities like, he just wants me to fill the void of his ex, or he just wants to try and use me for sex. I cant just let things happen. Please give me advice for I feel if I keep doing this I will never be in a relationship and I will be depressed all the time!