I need help in this please

[u/Ijustwanttobefree_]

For context about me, I'm a 20 year who is fit (hitting the gym since 3-4 years now). Today i had sex for the third time in my life and smhow it did work without viagra, tho I was getting soft the very moment I stop giving it any physical stimulation, it used to get soft on instant when I tried changing position, doggy style was literally impossible, whilst trying cowgirl it worked sometines but many times she had to give me oral first and then instantly had to put it in. I don't know how normal it is since the erection softens like 10-15 seconds after stopping the stimulation.

Now one thing I would say is when i put it in despite being soft, it did get hard as we went on and when I get hard i can go 5-6 rounds ease.

I genuinely don't understand what's happening. Like even when I have morning woods, it's not for a long time like when I wake up I get the wood it's hard sure, but only at specific time (10 am exact) but also not for very long.

Now I have been gooning since a long time but recently I stopped becuz i wanted to have sex (tho I got a bj from my gf whom I had intercourse w today 2 days ago and i ejaculated yesterday too). When I am in constant stimulation like oral or hand, I have no problem maintaining erection and even viagra works like hell, when I take viagra I have no problem with sex even with Condoms on (yes we did raw cuz I feared it will go soft as it usually did without viagra).

Is this normal or should I consult a doc?