I hope you find some professional help because it sounds like your distress is great.
As for thinking and thinking, I call that zoning. My T tries to say its okey. But, it annoys me because I need to get my but off the couch/floor/bed and get some things done. I waste too much time just thinking about things. I would suspect it is depression like you said because depression has a lack of motivation as part of it. I sometimes lack the motivation to do much except sit around and think. It might help to make note of what you think about and share it with us or someone. We might could help some.
But, I hope you find a way to get help where you are from a psychologist/counsellor/medical doctor.