Hey man, I really relate to the way your mind works, this happens with me too, I overthink everything and am always looking for the next thing that could go wrong. At this point I still struggle, but I used to have it really bad, and I couldn't even leave the house at one time in my life..( I touched on this in one of my posts recently if you feel like reading! )
But I just wondered, what do you do to 'let loose'? Because I've found there are certain things I can do that shake off the anxiety for a while, and as long as I keep up with these activities I stay on top of my life without worrying too much. Like going running, or cycling, getting my heart pumping makes me feel so much more free in my mind. Or even just a long walk . And do you listen to music? Because for me certain music can just change my whole outlook on life, there have been times in my life when music is the only thing that seemed to empower me. And this is before I played any instrument.. I just used to hang on it, if there was a message in the lyrics or even just the music itself that I could relate to then it would lift me up and stop me thinking negatively. And the same with films, if I feel like something is speaking to me in a positive way, I can carry that with me for days and I do that all the time, I actually only just rediscovered this recently, I had forgotten how important this was to my mental wellbeing and Reverted back to some serious suffering because of it!
It may be something else that works for you, but whatever the activities are you need to find them,and get out of this cycle by making them habitual.
Hope that helps you in some way..