How do I stop blundering pieces?

I'm stuck at low elo and am genuinely considering some kind of mental disability due to my talent at absolutely throwing games. It doesn't matter how long I look for - if I take my time, I lose on time, if I don't, I blunder pieces. I don't know what to do and don't even know why I'm playing at all when people start 2x my elo and I'm having to unironically CLIMB my way out of it fighting my stupid impulsive brain.

Its pretty easy actually.

Every time you want to move, check what exactly changes on the chessboard.

As a simple example, just check out the first game in the first speedrun by GM Naroditsky:

https://www.youtube.com/watch?v=Ytkf3qZTj74&list=PLT1F2nOxLHOcmi_qi1BbY6axf5xLFEcit

If however you play short time controls, you may simply want to consider to play longer ones.

Famously Magnus Carlsen himself missed a checkmate in one against Hikaru Nakamura in a blitz game recently.

Human beings are simply fallible, no way around that.

mentally disabled people wouldn't know that they are disabled.

you probably need more practise.. try not to be goal oriented, take your time and enjoy the journey.

and about your question, play longer time controls (with increment).. and don't play the first thing coming to your mind. see if there is anything better.

like Marias said, when a piece moves, it leaves some weak squares behind, try to see what has changed, and how you can use it to your advantage.

do the same for your own moves (before you move) try to see what kind of weaknesses it is gonna leave behind. it's called visualization. try to visualize it..