As you can see from this link, there is no FDA approved test for oral HPV. That PCR test was not going to be accurate for what you have. Oral HPV is actually very treatable by removing the wart.
Your depression lowers your immune system. Get some therapy. Meditate. Eat very healthy. Get more rest and sleep. Take vitamins and supplements that boos immune strength. Don't smoke cigs and don't drink alcohol. Exercise often. Lose weight. Do most of these things to get your body strong enough to fight the virus and boost your self-confidence. The cancer rate is very low. Do not assume you will get it or will get it in the next 30 years.
I'm sorry that you are going through this. There is currently no test for oral HPV unfortunately. There are a lot of unknowns about HPV, but if you are going to worry every day for the rest of your life that a cancerous growth might occur, you will make yourself miserable. I am in the same boat as you, but the fact is that 90% of the time, the virus clears from the body. You treated the symptom well with the medical professions. The stress will make all of this worse; my advice is to try and forget you have HPV, first for 1 hour, then for a day, then for a week, to try and create a sense of normalcy in your life.