Please Respond!! thick clear mucus from vagina constant throughout cycle for 6 months

For the past 6 months, I've been dealing with a thick, whitish goo coming out of my vagina almost consistently--not partial to arousal or the time of the month. It's so thick that it soaks my underwear and drips out when I go to the bathroom. There is so much that it irritates the mouth of my vagina and makes it itch. Often times, it hurts waaay at the end by my cervix during sex. Until 6 or 7 months ago, this would never happen and I have been sexually active for about 6 years now. I am in my early 20s, and starting to get nervous. I have had a yeast infection before, and I know this is not such an infection. I have gone to the doctor several times, once overseas and twice here in the states to check on various possibilities, and have since concluded what I do NOT have: My PH is normal, my cervix looks normal, it's not HIV, Chlamydia, Gonhorrea, yeast, or a (typical, at least) vaginosis. I don't think it's trych because the goo is thick and cloudy white, and not bubbly at all. I’m not on the pill, I’m not pregnant. I was on the pill for only two weeks last October, and was having a bad reaction and stopped all medications at that time. I guess it’s possible that I’ve been having trouble since then, but I really don’t think it should do that much for so long, and I’ve never heard of this happening…The doctors are saying that they can't see what it could be, but I know my body and I know something's off. It doesn't smell BAD, but it doesn't really smell like me...I've been reading some of the other people's notes on here and other sites and the people who are experiencing the same thing haven't seemed to find any answers. PLEASE HELP!