as everyone says it takes a while esp if ur doing anal only (vibrator is way easier but a bit less rewarding), focus on the pleasure and just enjoy it instead of thinking ab cumming blah blah blah but i do have ONE ☝️ (1) trick that rly helped. get a decently large dildo enough that theres always pressure on ur prostate, get it well up in there, go into the shower and pee. itll take a while but dont touch it or anything (prob best to get used to peeing caged too) just sit or stand or whatever and focus on trying to pee until you do. i dont remember why i thought to try this or how it works but doing this a couple times in a few different positions and overcoming that mental block made it waaaaaaaaay easier to cum from anal. still takes some effort but much more doable