Just in case you weren't aware, this is a very classic symptom of ADHD, you might want to check out the other symptoms and resources online to see if it fits you. There's medication for ADHD which may help? I have ADHD, so that's why I'm sharing.
A tip I once got was "three before me", which means every time you speak, you let other people speak 3 times before you add anything else. I find that helpful if I can remember to do it.
When I think of something to say, I feel a strong urge to blurt it out - partially because I am excited by this amazing thought I just had, and also partially because I'm worried I might forget it.
Another thing you can do is take notes of things you want to say, write them down - that also helps you evaluate if they're actually worth saying!
There really should be a law requiring companies which provide online services to be required to release self-hosted server software once they discontinue the provision of the service.