sounds like a really tough situation. Now I dont mean to encourage lies in a relationship but is there any way you can go to therapy without his knowledge? It really is important and helpful to have therapy. Or is there a chaplin or church type person that may be able to talk to you?

There are also some therapy courses online such as CBT, they are free and easy to access. Maybe you could delete your browser history after doing them? What about self-help books? Some are actually helpful but they might be hard to hide. Just some ideas for you