I do get like this often, and not just when depressed. My mind is always going high speed, even when I am depressed.. it never stops. When I am manic it's really bad, I can't even make out the thoughts because they just become little pieces of words. I am not sure my experience with that is so common, since many people complain of slowed thoughts with depression. Because my mind is so fast I find it really hard to focus and direct my energy into getting something done. Ahh sorry, you are talking about looping thoughts, and I am thinking about other stuff, sorry.

But the not being able to get stuff done, I always make lists. Every morning I sit down and make a list of what I want or need to get done. Then I go back through the list and number them in the order to do them, and group together the things that i can multi-task on, and mark which order to start those in. Maybe a little bit much but it helps me get moving and get stuff done. Plus I love the feeling of checking them off, a visual for me of what I accomplished.

Sometimes I try to to remember how good I feel after I get my stuff done and that can help motivate me a bit. Or I use the time I spend doing chores and stuff to practice mindfulness.. which helps to de-stress me.

I also give myself small rewards for getting my stuff done, because procrastination has always been a problem for me, and depression, but I do know that once I start getting back into doing, the depression does lift somewhat. Just small rewards like getting my favorite coffee, or some time with my sister ... could be anything.

I don't know if any of that would help you, but I know it does help me.