When I masturbate it stops feeling good after a while

Whenever I masturbate it feels really good for like 30 seconds and then as soon as I get really into it it just stops feeling good??? Idk if that makes sense but the feeling just goes away and I can’t ever get beyond that point.

I’ve tried stimulating my clit with my fingers, a vibrator, I’ve tried the shower head thing and I’ve tried fingering myself but I feel like nothing makes a difference.

I don’t feel nervous or guilty or anything when I do it so idk what’s going on. Am I doing something wrong or is there something wrong with my clit?? Help 😖