In simplest terms, speed comes from confidence.
If you have confidence that the bike isn't going to "crash" then you can comfortably ride well within that limit.
The closer you get the the point where the bike is about to "crash" the more nervous you (are supposed to) get. Its nature and its why we ride bikes. Its exciting. An Adrenaline rush.
But there is a point for everyone where Self preservation cuts in and your body and mind (not you, this is on a subconscious level) decide despite you being there and supposedly in control doesn't matter and cuts in. You tense up, panic sets in (to varying levels) and "you" are no longer in control. Your subconscious is. We've all gone into a corner a little too hot and had that panic moment.
If, for you, this happens earlier than other people you have to face the fact that you'll never be as fast as them. You can increase the level at which this cuts in a little by practice and familiarity with "going fast" but at best you'll get to a level where you are marginally faster. lets say 20%.
But if the other guys have this stimulus 30% higher in "speed" or "lean" than you do, that means you'll never keep up... and you'll never catch up.
Now this is nothing to be ashamed of. Its nature and you can't change nature. If your stimulus cust in early, its just the way you're wired.
However, you can do things to increase confidence. if you're on a bike that has 180bhp and you're unsure of it, trading in for a bike that has 70bhp will allow you to me more confident that it isn't going to bite you in the ****.
Using track tyres gives you confidence that the tyres are as good as the guys that are coming past you at 60 degrees of lean. If they can do it...
When on a track day, increasing speed, lean and braking point very *gradually* leads to an increase in confidence. " Bloody hell, I thought that was too fast and I didn't crash"! The joy of track days. Then you'll have a slide or some such and it'll knock your confidence. and it takes time to build it back up again.
When I crashed at the last meeting at East Fortune in practice (I'm a numpty!) I couldn't take that corner as fast as I usually do despite really forcing myself to. I was about three seconds a lap slower despite trying to overcome my "fear" of that left hander. No matter what I did, my self Preservation button was being pressed by my subconscious and was in control for the rest of the day.
So, waffle over, You can increase your confidence with familiarity of the track, bike, tyres, speed, lean etc but it takes time.
However, if your start point is poor body position, poor track position and fear of a bike, then the best way to proceed is tuition. Tuition from someone who *Knows what they are talking about*!!
Grab an instructor on a track day and listen to what he says. Progress may be slow as you are countering your natural "Self preservation" reflex and thats not an easy thing to do and your (conscious) mind might be telling your body to do one thing and your Self preservation (subconscious mind) might be over-ruling it, but you will make progress.
and buy a smaller bike!
C