I have a similar problem. I've slowly come to grips with it by playing more solid/positional chess, and altering my repertoire in favour of less popular lines.
I'm also working on my endgame skills. I come to realize that patience is key.
Now my results against weaker players have improved, but my results against peers and stronger players have deteriorated
Guess I haven't found the right balance just yet...
Yes, patience and quiter positions whereby the weaker opponent makes many of the decisions. Extremely sound advice
@teichmann
there are examples of people becoming a master later in life. not many. but some.
There are actualy quite a lot.
If you're rated 2199 at age 12 then yes, there's a very good chance you can be 2200 at 30.
If you learn chess at 30... well, there have been MANY topics about this on the forums, and not 1 person has been named yet.