Hi...I know it's a bit late but if you aren't still around maybe my response will help someone else.
I experienced the exact same thing you are describing only I'm 47 and I've always had fantastic orgasms. That is until menopause started. It was so depressing.
It was so bad I finally went on hormones. After just one estrogen pill my orgasms improved 80%! I'm hoping after some more time they will go back to normal.
The problem therefore could be your estrogen levels not testosterone.
My girlfriend has the same problem, coincidentally she is 17 too. Its frustrating for me cause out of no where she decides to stop n says it feels weird to keep goin. She also said the same thing happens when she masturbates. it seems like she's getting close then it just ends.. idk what it is. its not my size and she is very aroused during sex
Yeah neither if those worked though ><
dude trust me you need 2 have the love connection or try masterbating MASTURBATION IS THE KEY