Everyone who climbs suffers from this to some degree, so you need to accept that doing this will make you scared.
I've had very similar issues to the one's your describe over the years. I've tried several techniques to help with this with mixed result. From my personal experience the below didn't work for me (they may for you)
- Fall training, i.e. taking a fall deliberately to get used to it.
This helps with your fall technique but for me it failed to address the issue. I wasn't scared of taking a controlled fall I was scared that I couldn't hold on while clipping, etc.
- People shouting encouragement/telling me to get one with it
This just annoyed me/made me more frustrated than anything, which made me not want to get into that situation even less, which made me more annoyed at them and me, repeat until I end up shouting at them to simply p**s off and storming away from the crag in a terible mood.. :)
- Putting pressure on myself to succeed
Partly as a result of the above I ended up getting into a mindset that I was just being silly and I should just man up and get on with it. again, for me this simply made the matter worse, to the point where the grade I could lead gradually got worse.
This is where you visualise the moves and convince yourself you can do it, etc. Bit too hippy for my liking, I just couldn't do it. :)
Ok so what did work for me:
You will get scared, that's fine don't fight it just accept it. "Ok I'm scared, now what". This helps you think thought he panic.
- Turn your brain on to fight your chemical response
Panic/fear is a chemical response to being in a dangerous situation. Your body is flooded with Adrenaline and you go into fight or flight mode. So do you fight or flight? Well neither your 10 meters off the ground attached to a rope, neither option is helpful.
You have two options, fall (fine your not bothered by this but ultimately this just releases more adrenaline and makes matters worse) or engage your brain and out think your chemical response. Start concentrating on what's around you, focus on your breathing, get this under control, your safe remember that, where's the next really good hold, I need 5 mins to just get myself in order, try not to down climb but if you do, do it slowly and controlled.
Try and wait it out. Don't simply let go and don't down climb. Wait, close your eyes, concentrate on your breating, wait for the adrenaline to die down to an acceptable level, then continue. Try and hold on at this point (as opposed to letting your belayer "take"), realise you can probably hold at this point longer than you realise. Rationalise the situation
- Try to turn the negative into a positive
So you get scared when you climb and get swamped with Adrenaline?! Isn't this why your doing this? for the buzz? The Adrenaline! Turn the negative into a positive. Next time you get scared, try and enjoy it! I know this can be hard but adrenaline can be pretty enjoyable if you learn to deal with the fight or flight response.
You get frustrated because your not climbing at your ability which make your more anxious which makes you push yourself, which makes matters worse, repeat. STOP, go for a boulder, relax, enjoy yourself, the wall's not going anywhere and you can come back whenever you want. Your supposed to be enjoying this!
The above is based on my personal experiences. Different people will react differently to this. You need to find a solution that fits you.
A nice story
For me the turning point was when I was trad climbing, outdoors. I was leading an easy(ish) pitch but it was harder/more exposed than I'd expected. I found myself balanced on an arete 3-4m above my next placement which (in my head at least) would never hold a fall. I couldn't take a fall here, I had to get my sh*t together or I could hurt myself (in reality I was probably perfectly safe but I'd worked myself into such a state that I felt in real danger). I sat there slowly praying looking for a placement and not finding one, gradually I started to feel better,
"hold on this hold is solid, I could hang here one handed for about a minute easy"
"Now my legs stopped shaking that foot placement is about the size of my living room"
"There's a crack there, why the hell couldn't I see that before?, what's that? a number 10"
"Bloody hell I could hang a mini off of that placement"
It suddenly occurred to me that indoors I would of just let go and become annoyed at myself. But by sticking it out I'd overcome it. I felt awesome at the top and jumped about like an idiot. My girlfriend didn't understand what the fuss was all about, "That was easy?!"
Whenever I feel like I'm loosing it I try and remember this situation and how focused I felt once I'd gotten control of my emotions.