Sex and stds

If it’s been 3 years since I last had sex with my boyfriend we decided to wait for marriage we used condoms every time except for once or twice for a couple seconds just in and out but recently I’ve been having subtle every once and a while pain in my vagina up in the clit area or labia area it hurts when I wipe sometimes and stomach pain there’s been a couple times where I have had a ton of clear discharge in underwear any advice ?? I have been eating bad lately and not drinking enough water but could it be an std or dehydration heat rash ?