Continuous Stringy light yellow discharge, no BV, no STI, HELP!

So ive had a goose hunt trying to fugure out this discharge. Ive had it since September last year, yes a long while now, im 21, never been sexually active (never had oenetrative sex per say, i have however recieved oral by my boy which i thought may have been what caused this increase in discharge as it was around the time we were doing that, that the discharge increased). I thought it was BV, came back negative, only thing testes positive was a yeast infection so they put me on the cream & pessaries. Did absolutely nothing, then they precribwd fluconazole, did 4 weeks of it, no luck, then they increased the dosage, still no luck, they tested for clamydia even though i was pretty confident i didnt have it as i have no itch, no odour just the stringy, white to yellow discharge. Its been doing my head in and frustratint to wear a liner everyday. I thought it might have been the Bc pill and i have been now off it for two weeks still discharge. Anyone know what this could be?

In terms of sexual activity, the o ky activity I found worrying was at times my boyf was a bit rough with the fingers if you know what i mean, could that cause vaginitis?

Any help on this would be great. It does look like cm though but its literally every single day