How can I fight intrusive thoughts and compulsive rituals?

My mind tends to fluctuate between extremes - either follow specific nonsensical routines to the tee, or conclude the day as a write-off if these rituals don't "feel just right". They are completely irrational, but I HAVE to repeat them over and over until they "feel" like they've been done properly. Like, sitting down in a chair a certain way, spinning around when entering a room, stupid little patterns like this.
The more I repeat to achieve that "magic feeling" without success, the more frustrated and exhausted I get, and I can never get anything done. But on the other hand if I try to just push through and break these rituals, intrusive thoughts invade like sirens and won't let me have any peace or focus on ANYTHING else, leaving me a hopeless wreck.
How can I take more control of shutting these intrusive thoughts up? Again, they make no rational sense and I KNOW that, but I can't seem to find any peace or sense of control unless my brain decides that my routines have been fulfilled to standards.
I tried everything - forcing to carry on without going back to repeat anything, but the alarms just sound louder. Tried rationalizing with myself, but that doesn't dissipate the feeling of things not going just right.
Usually this cycle consists of a couple of good days, then one or 2 days of being tired, but this "rut" phase has been persistent for a few days now and I'm feeling more and more hopeless.

What are some specific strategies to SHUT THESE THOUGHTS UP, and not get stuck on mundane actions for up to hours on end?

(As an aside, I do see a therapist and go to a support group for my mental struggles, but of course it's still a constant battle to keep myself somewhat functional).

When it comes to having OCD compulsive rituals are most of the time associated to the thoughts, what i mean by that is:
1. You get a thought.
2. You begin to "Obsess" over the thought.
3. You begin to get anxious over the thought.
4. You perform a compulsive behavior to neutralize the thought.
5. The anxiety goes away.
Now regarding this issue is the entire cause of what OCD is in general, when it comes to fighting compulsions you must pretty clearly do "Not" what the ocd wants, and sit with the anxiety/discomfort. I know it feels like it will last forever, but it dosnt and it never will.

Regarding the thoughts, you cannot stop them, because thoughts are not the problem, the problem is the association you have to the thoughts, the first step to overcome OCD is recognizing when you have these thoughts and doubts, once you do your capable of talking back to the thoughts using logic and overwriting the OCD emotional part.

I can share you with some techniques i did to overcome my own OCD, i know its a pain believe me. But when it comes to overcoming OCD you must be willing to experience some anxiety.

As long as you perform compulsions you will only make the obsession become stronger, because you link this anxiety reducing ritual to how threatening the thought is. But the thought is not the problem, the anxiety is. You will in fact increase the meaning of the obsession by neutralizing.

For example:

A guy on a bus is constantly clapping his hands. People wonder why he's doing so and ask him what it's for. He responds "If I don't clap, it'll rain pink elephants" "But there aren't any pink elephants around?" "I know, that's because I'm clapping my hands"