Fangface, I felt exactly the same as you when I first started playing sim online - I got absolutely owned by this guy Roberts333 or something. But he enouraged me to continue, and once I did get a kill I was hooked. Seeing that fireball is so much more satisfying when you have worked so hard for it.
Even though you know your flight stuff, there is
always a lot to learn when you go online with any game. Like if you completed CoD on veteran you would still get owned for a while online. Or you've finished Red Alert on the hardest difficulty - yep, owned online...
It is incredibly demoralising - especially when you don't get credited with kills. But that is what makes it so rewarding when it comes together. I would stay away from dogfights without a shadow of a doubt. Team battles might be slightly better, but target ID'ing tends to get me killed a lot. My advice would be to play CTA - and if you can't find a game, host one. People will eventually join. 2v2 CTA with 2 airfields would be my ideal learning playground