Install the browser extension Unhook. It hides all recommended YouTube videos, so when you watch a video you aren't looking at a bunch of other videos to watch. It's very customizeable, so you can choose what to hide.

Create a list of what you want to be doing and consider attaching it to your monitor or putting it just to the side so that you can easily look at it. When you feel stuck, look at this list and do something on the list. Ensure the list includes some easy to do things on it like maybe "go for a walk", "read a book", "play instrument" etc.

When trying to change habits, start off small and simple. For example, if you want to start running each day you might start by putting on your running shoes and walking to the end of the driveway and back. Start off so small that your brain can't talk you out of it.

I create daily todo lists and feel satisfaction from checking them off.

Try some ideas and see what works for you. Good luck!