Nothing wrong with a late night walk. I am very homebound but a somewhere between midnight - 3AM walk helps me unwind as I try to look at landscape, trees, the brick roads... Or if I do not go out I pick certain types of late night TV. Old time twilight zone shows suck me in as they are weird and interesting but not up to date enough to freak me out or seem realistic. I cannot do music to relax unless it is new age. I used to think it was all crap but found it really helped, that and nature sounds. Music holds so much emotion it is almost pointless to use it to relax IMO.

Chamomile tea and "Celestial" teas makes a "Sleepy Time" version which is very mild and calming. I drink mine over ice as I do not like hot. Also Lavender helps a lot. They make bubble bath versions.

Heating pad on the back soothes too.

Stretching.

A massage if someone is available. If not they have massagers that you can use on your neck and Dr. Scholl's has a really long one that bends so you can reach any spot on your back and heats up.

Scented candles help too.

And most explore the thought. Don't push it out. It is there yelling at you for a reason. So pull it apart. Journal like you have been told over and over. What emotions does it bring? Beyond anger, what fuels it? I am just guessing anger as it seems to pretty normal. Just get it out. Then the other above will help a lot relaxing. But until you process what you are thinking about it won't go away. You may be able to tuck it away briefly but it will show up again.