I can't seem to trust anymore, triggers, depression, insomnia

Hello everyone. I didn't know where to go for this so I hope I am in the right forum.

Last year I received a huge blow to my heart, a girl I had been seeing for 7 years ended up getting pregnant by someone she'd been seeing on the side.

It completely devastated me. And I spent a bit of a month wondering what I did wrong for her to just move on from me.

A few months later I decided to try an online dating site and met a girl who was very much like me. She was kind and sweet and understanding. But upon talking about deeper subjects she revealed that she had slept with a majority of men from both work and on the site. For some reason I felt like cutting communication, since my prior relationship showed me that promiscuity lead to cheating.

But I swallowed my feelings and gave it a shot. I thought it would go away and I'd be happy, but I've been able to spot certain signs from her that makes me think she's tired of me or seeing someone else (like my ex was) and I'm not sure if it's just my paranoia or real "gut feelings".

I'm starting to lose faith in her even though she hasn't shown any red flags, besides some times where she's "too tired" to Skype and I think that I'm just looking for signs.

I'm not sure what to do. I love her but at the same time I'm really scared of getting hurt. I've always had abandonment issues, since I've always been lonely most of my life. And people who say "I'm here for you" end up leaving.

I'm getting to the point where her words sound empty and I never really hear reassuring words from her.

What should I do? I could try and talk to her but what if she's just lying through her teeth? I feel as though her presence alone triggers me causing me to lose sleep. How can she be toxic if she hasn't done anything wrong? Am I Just crazy?