how to deal with regret?

As a chronic overthinker, I've recently been dwelling over the fact that I should have taken philosophy over chemistry. As much as I love chemistry, a level chem is draining the love I had of it at GCSE. I loved rs at GCSE and I genuinely think I will regret not taking philosophy at a level. I also really regret the fact that I don't have law as a uni option as all my subjects are stem based. To people on this sub who regret their options, how did you deal with it?