Chin up!
The +- vs each player can vary quite quickly as a $200 dollar win for one player results in a $400 swing in the +- vs player figure.
When I joined the site I made some big bluffs after I thought you trusted my play and you picked off every one! I think I was $1000 down at one point just vs you.
As to what changes you need to make I think radical changes in strategy can be counter productive, but slight adjustments might be necessary.
It sounds strange but in a HU you need to get your opponent to trust the way you play. They should feel that they understand what you are representing when you make certain moves.
If you get caught bluffing the trust breaks down and you need to re-establish it.
It’s been interesting to see how indivudual matches develop over time. At the beginning both players are very tight preflop. Then they open up and make more flop bets. After a while some re raising on the flop occurs. Then this becomes standard and there is more floating, 3 betting etc. Finally the ‘play’ moves to the river as no one trusts each other and the decisions are made by big all in bets etc on the river. I think that’s the point we got to in our big flush draw hand!
So the challenge is to tone down the aggression just a little so that even if I think you’re tilting I’ll lose due to you making more big value bets and me calling looser. But if you tighten up completely I’ll probably keep stealing off you and it will be easy to know if you have a hand.
….. of course now we’ve discussed it all you will probably take that into account and adjust a few levels further….

That’s the beauty of HU no limit.

For what it’s worth it was a tough slog getting back to even money with you and I think you’re game is solid.
I’ve been playing online a little HU and doing much better since playing you and others like Teppo!
Regards
Zach