Don't worry, i'm worse than most people and yet i do fly online from time to time.
Like in every other field of human endeavor, there are people who will be better than you and people who will be worse than you
You'll see that the more a simulator models, the more ways you have to be good. Back in IL2 i was flying 190As. I was generally good at picking my fights and not getting into tight spots, plus i knew how to shoot those 20s out to a range of 500 meters. Now in CoD i keep doing the same and i'm also good at keeping my engines running. The flipside is that by not pushing the aircraft and my luck, i don't often explore the limits. So, when i do get caught up in a situation i can't control, i'm not skilled enough to overcome it.
Other pilots mix it up much more aggressively and get shot down a lot more often, but through all this they also learn what do in such a situation and prevent it to some extent.
Nowadays i mostly fly bombers or twin-engined aircraft because i also like the challenge of planning a sortie, monitoring the various aircraft systems while navigating, etc. Most of the time you won't see me as the guy executing a perfect energy managing maneuver to land on your six in a dogfight, or even a high speed bounce. Most of the time, i'll be the guy that you don't see, who swings around half the map and comes in from an unexpected direction, drops bombs on the target you were supposed to be protecting and hightails it back to base while all the fighters are busy chasing each other's tails
As you can see, there's a lot of different things and you're bound to be good in at least a few of them. Plus the majority of people online are very helpful and friendly, not to mention that flying wingman with a couple of experienced pilots makes you better in handling the aircraft as well, simply because you are following their maneuvers.
I'm not much of an onliner either, but there is a lot to do once you scratch the surface and a few extra things to learn, which will in turn enhance your enjoyment of the sim when flying offline as well.