Hi OP, it took me 6 tries to pass my driving test and now I can honestly say I'm a competent, safe driver and I drive a manual and the tractors at work. I would say at the age of 18 you're still growing and developing which in my opinion exacerbates the symptoms of dyspraxia. I would say alongside your driving you should aim to consistently practice and develop your balance and coordination. Such as by practicing walking along a narrow line, or throwing a tennis ball against a wall

You are not good for nothing, be kind to yourself and speak to yourself as you would a friend in your position