After Sex Creams/Remedies

So me and my boyfriend are long distance which means I have sex every few weeks to a month. Most of the time we have sex about 3 times a day which is a lot but I have noticed after the third or fourth time the bottom part of my vagina opening gets randomly irritated kind of itchy.

We both have recently been tested for stds and stis(as far as you can get rested) so I don’t believe it has anything to do with that. Since it all came back negative and this irritation also happens when I masturbate with a dildo (which is don’t do very often - normally I just use my vibrator)

I believe it has to do with not have sex for period of time and then over doing it because it feels like the bottom part has been rubbed too many times.

Anyway the main thing I do is clean my vagina area and then put some vaseline or petroleum jelly on and then throw some big granny panties on. And it feels better and the irritation goes down after a day or so as long as I don’t have sex or masturbate.

I was wondering if anyone else has this issue and if there are any creams or anything that you guys use to help with the irritation

Thanks for any help :D