Help please

So recently i had sex with this one guy i know very well. And the thing is that after the sex i think i got an infection because my vagina itches so much and not my external part .

More like the hole part (sorry didnt know how to explain). It been quite a few days. Maybe about a week or so and im thinking about going to the doctor but meanwhile i dont know how to relieve this itch. Its really bad. Any advice what i should do?