Rumination has easily become my worst compulsion. Does anyone have any good tactics on how to stop it before it makes the intrusive thought worse?

You should look up “rumination is a compulsion” by micheal greenburg and OCD stories , it’s extremely helpful and help me cut down my rumination a lot

One of mine also

The mornings are usually when I feel the urge to ruminate. I was reading "The OCD Answer Book by Dr. Patrick McGrath" and he gave a good tip. He recommends to respond to intrusive thoughts by saying, “Maybe that could happen; who knows” or something even more basic such as, “totally”? So instead of spending your day in complete disarray from attempting to disprove the thought through rumination, you would allow it to occupy space in your head as it pleases, letting it fluidly come and go regardless of its meaning. With rumination, you might want this mythical "aha" moment where you can just feel totally confident and certain but unfortunately, that will never happen because nothing in life is ever that certain - and for those with OCD, OCD just keeps raising the bar more and more for what you need to do in order to get to this place that really can't happen at all. Research actually shows the more you engage in the checking of your memory, the less confident you become in your behavior. It sounds counterintuitive but essentially the more you check locks, stoves, or your own mind - the less confident you become overall. Try to resist and reduce this rumination. Recognize when your brain wants you to answer a question and then try as hard as you can to not answer the question. I was looking at the comments and I'm now listening to"Rumination is a compulsion” by OCD stories with Micheal Greenburg! It's good! I recommend checking it out. It might also be helpful to check out NOCD's support groups. They have a "Dealing with Mental Compulsions" group that meets every Monday. https://www.treatmyocd.com/support-groups

Try focusing on things you like to do. It’s easy to fall into it but the best thing you can do is cutting it off as soon as possible.