Why is it so hard for me to make changes and let go of a bad lifestyle?

I have depression and compulsive thoughts- I cant seem to change, in my head i think i need to hit an even lower or lowest point before change, so i keep waiting and cant. Its not the right way but i cant get past it. Its like i want to feel as worst as i can first as motivation but thats not right. I dont seem to muster up another motivation to change but i want to! When i make a change i always cant manage to keep it because i always doesnt feel official to me which is my compulsive thoughts. Dont know what to do?- I see someone and take medication but in a way it has to be me that does the change.