What Causes Lack Of Sensations During Masturbation?

Hi i am having a problem and i don't know what to do i am embarrassed to go to my GP and ask this so i hope you can help me and i see you have extensive knowledge in this field. I started masturbating and ejaculating since i was 13. During this period i did have a problem where on the left side at the base of my penis head i had the foreskin stuck on the penis head so i couldnt pull my foreskin fully back and over months i used to try and detach the skin from the penis especially in the shower as i used the water pressure to help remove it. Which worked after a while. Then months later like 14.5 i could not achieve an orgasm i could ejaculate but no sensation no tingly feeling in my body nothing. I used to feel tingly from my head all the way down to my toes. I also tried to hold myself when i was about to ejaculate so i could achieve an orgasm and continue after. Could that have an effect from forcing semen back inside. Honestly i don't know what to do i have no sensation when i masturbate i have never had sex before. What can i do to achieve an orgasm and why have i stopped getting orgasm. I have heard of ejaculatory anhedonia but not sure if that is a correct diagnosis or secondary anorgasmia. What do you think. Also how can i fix this Thank you very much