First days!!

Hello everybody!!!Here what happens with me. My ed is a little bit weird. I can have strong erections while masturbating with or without porn but if I stop touching it it floats again. I mean, can 't maintain it mentally.The same thing happens with sex. While having sex, I masturbate till I have a strong erection and then I wear condom (which is the difficult part), and start having sex.Sometimes successfully, sometimes not. Sometimes while having sex, I lose my interest and try to think a porn stuff in order to get erected again. It's exchausting somehow.Is anyone here having the same experience?