You are pros, help me please

Hello friends. I need a little help here and maybe you can know solution for my problem.

I like prostate play, i dont do it much, but when i start, its nice. I can find my prostate with dildo or fingers well. Problem is, during my fun time, its intense and hot, but in some time, after maybe 30-40 mins, it starts feel like i "lost it". I dont know how to describe it better. Its great but at some point i start loosing nice feelings and it starts to be like "meh..."

What I am doing wrong?

Too much, too hard, too long time? Mostly i used dildo(prostate dildo without vibrations) by my hands. I dont have toy with suction cup so i dont ride it. My playtime is mostly 30-50 mins long. No rest times - can this be a problem?

I want to achieve HFO so much...

Today I ordered Njoy PureWand. Maybe this will help me to "climb over obstacles"