Trusting & Letting the Pain Go

Three years ago the greatest and the worse thing happened to me . I became pregnant with my son and his dad and i weren't on good terms. As I found this news out to I decided to give "us" another chance. Long story short that was the worst decision I had ever made . That relationship really took me through a loop I was at the lowest I could have ever been in my life . Now I'm the present day here I am a single mom looking for love . I've talked to two people after my ex and it didn't work out. But here I am now in a relationship of 5 months now and I can't find it in me to fully trust again . I think everyone is out to get me . I overthink too much . I can't seem to lighten up I'm always too serious . I need to find a way to get back to me.