How do I stop obsessive thought's about the world. I live in fear everyday that I am in a dream.

Same way you stop other obsessive thoughts, you don't. That's the easy answer, haha but hear me ou+t. You can't control your thoughts no one can, but we can control how we react to our thoughts, should we worry and pay attention to every thought? No of course not. Even you disregard thoughts that aren't about your theme without even thinking about it, when you get attached to a thought you tell your brain that it is important and your brain keeps it on loop. The way to break this cycle is you do nothing to neutralize this thought, you just let it be you don't analyze it you just see it there and go about your day, the thought will go away, it will come back but the more you disregard it the less frequent it becomes and the less anxious it makes you, eventually you get to a point where the thought might come up but it won't bother you, don't try to justify the thought or argue with it, it's only a thought, a brain fart lol best of luck friend, God bless you, this world is way too real to be a dream. God loves you just as you are.

I have that you have to accept maybe maybe not but you know there is world you enjoy it and one thing in dream there is no clocks in reality clocks are therr

You don’t stop the intrusive thoughts but you can choose to not pay them any attention, which in turn will lower their frequency and intensity! OCD feeds on attention, which is where compulsions come in. If we keep ruminating, focusing, etc on the fears and questions that OCD gives, in your case thoughts about the world and being in a dream, then we continue to be stuck in the cycle. I have similar fears at times with maybe being in a dream or that nothing around me is real (also known as Existential OCD), but I have to learn to be okay with the uncertainty of “maybe I am in a dream, maybe I’m not”, ERP helps a lot with this. Taking away the power from OCD in that you don’t do the compulsions will make the fears less and less scary and over time it won’t pop up as often or even at all. I hope this helps!