I did go back and read your original post. Yes, you had a valid reason to test and you have done so. Today's standard is that if you are negative at the 3 month mark, then you are negative. The only people that take 6 months to show antibodies to the test are those people that have additional health problems. A test at 3 years out that is negative, is definitely negative. So that is great news!
Now why is this bothering you more than 6 years later? I understand that there is a stigma attached to being HIV positive. I understand that you had unprotected sex and put yourself at risk way back when and scared yourself. This has become an obsessive irrational thought for you. It also looks like you have put your life on hold. No dates, no sex since that time? There are plenty of ways to be safe. I think that since your partner cheated on you, it has left some emotional scars.
So at this point you are afraid to be with another person because you feel there is always an HIV risk and you are probably scared also to be with someone because you got hurt last time. These are two issues that you have to address.
You are doing the whole What-if thing which is classic OCD. "What if they mixed up the tests?" "What if the results aren't reliable?" You are also doing the "doubt" thing in doubting the test results, also a symptom of OCD. Playing with your hair may be a compulsion you do to relieve any anxiety or stress you are having at the moment.
Have you considered talking to a psychologist about this? I really think it would help. You really have been held back from living a normal life by these thoughts. I believe you can get past this but it may take some outside help.
As far as the future goes, there are plenty of trustworthy people out there. You just happened to pick the wrong one. There are plenty of HIV negative people out there. Perhaps the best thing to do next time is date for three months, no sex, both of you get tested, make a committment not to cheat, and move on with your life, of course with protected sex every time.
Thank you for kindly taking the time to read about my situation.
I will start by saying that I feel aside from an intimate relationship, I have had a good few years. I graduated college a year early, just got a great job, and moved out of my parents house. I have good friends and family. I have never in the past 6 years felt ALONE, nor have I longed for a significant other... perhaps I have just deluded myself, but either way, I have had a very pleasant life since this all started, for the most part.
I do agree that this has become an obsessive thought... I will go months without worrying about it... and then I will go on for months where I think about it several times a day (all day?). I am never depressed, or visibly distraught. However, maybe it is time that I try to find someone that I can talk to about this. I will consider this token of advice heavily (as you aren't the only person who has suggested this). I keep thinking that I just don't trust those results because it was a home test kit... but I fear getting it done at a lab will leave me in the same situation I am in now (heh-- and of course my obvious fear that it will come back positive).
Anyways, once again, thank you for your time and advice.