I think my relationship is over

I think it's time to end my relationship with my little girl's dad. I am laying in bed filled with so much anxiety that my body is shaking. I have no friends anymore, changed relationships with my family, he checks up on me constantly. Always questioning my faithfulness to the point where I feel guilty when I haven't done anything wrong.

I feel like I am on the verge of a mental breakdown. I've never felt this way in my life! I'm so sad