I've tried so hard but in the back of my mind...

[PenguinPablo]

I don't know if I truly believe I will ever be happy... Or better yet, this sense of hopelessness.

[susanyzm]

Well, you may start by stopping trying to be happy. Start to know yourself. Dig deep into your hopelessness, not for the purpose of solving it, but for the purpose of understanding it. 

You can learn so much about yourself just by observing yourself. The grip of hopelessness will loosen once you see it as something worth looking at rather than something to battle with.