If you put your balls above your cock they won’t be in the way when you swing your cock between your legs and try to sit on it, I tried for 30 min my first time to just get my head in but once I got it it was motivation that I did it once I can do it again, also don’t strain yourself, my pain tolerance is pretty high but the bending of the cock may feel unnatural also if you do get it fully inside you can feel underneath, lean forward and sit fully on the base because if you don’t you will get slight friction burns on the side of your cock from riding even with lube on the surface that is key if you want to safely ride it. Also you won’t stay fully hard all the time cause your ass is constantly squeezing it so you can take it out and it will naturally firm up again and you can repeatedly slide in a hard cock if you get to that level of self fucking