Making up problems

I'm not this is an autism thing, possibly more of an anxiety thing but I'm aware many people here also share this difficulty. I am terrible for making up something to be worried about and then it locking in as a problem and not being able to stop worrying about it.

Today someone in work made a suggestion they thought would be helpful. I said no but didn't explain why. The person didn't push it and that was the end of the conversation. But I've now completely convinced myself because I didn't give an explanation that tomorrow this suggestion will be forced upon me.

I'm aware this is ridiculous and a waste of energy and am making myself feel for rubbish for no good reason. I've tried so many things to stop my brain spiralling in these situations. I try to distract myself, I try to rationalise, I try to show myself there's more evidence against this thought, I've tried writing it down. I really don't know what else I could to stop these endless spirals. As if I don't already worry about enough of life without adding made up worries to the mix!

Does anyone else struggle with this? Has anyone ever found a strategy that actually works to stop it?