Help me find a solution about that....

I'm engaged for at keast 8 long years with my wife. We're are both Haitian, coming from the North Side of the country. I was so in love with her, i can say until now i feel i luv her in a such unconditionally way.
But i caught her cheating on me so many times. One of them that i can't it take out of my mind is when i caught on her phone she slept with a police officer in a hotel. That thing destroyed me, and still destroy me inside and outside of me. But now my hands are tied up, because she's pregnant now.
But the biggest thing now, i can't trust any words from her. She's so unfaithful, that's bother me. And now we're gonna have a kid, i dunno what to do. I'm not in peace in my mind with her. I feel like she can cheats at any moment.
What will you do in my position?