What is the best thing to do if you feel this way but mess up your chance with your dream girl? Do you just give up? I would do anything to be with her but I messed up my chances what can I do now ?
If you haven't had a relationship with them it's incredibly easy, get over it. Relationships hurt, shared memories hurt, losing someone hurts, looking someone in the eye you once sat in bed and laughed with as though they don't exist, hurts, this sounds like a crush in the playground.
So i will assume its all broken up now and you were unable to do anything. What next? You have no way of contacting her?
No point beating yourself up. Why not have a chat with childline and see if they can refer you to someone who can help you with your shyness/confidence/ self esteem?
Is she going to uni? Do you know her address?
You could always drop off some flowers and wish her well? Ive kind of given up you will break the shyness in time and realistically she will be focused on exams and uni. You think you could manage that or too big a gamble? It would get you looked on favourably, she might talk or maybe when shes back from Uni she might wave say hello instead of forgetting who you are?
Well youve had moments and with you I dont think you cna do it becayse of the shyness. Confidence and the way you do it makes it seem more natural, but you will find that hard becaise you have put her on such a pedestal. As you dont really know her at the moment, she is going to uni, then it may look odd. there is a small chance she might be interested in staying in touch on an acquaintance basis, as long as you dont do anything weird an at least that means you cna keep in contact.
If it were some of the people on this site then they would find it natural to approach her and go for a drink or even a date, because they havent built the whole thing up into this impossible thing that you have. Thats what you are going to have to work on whether you stay in contact or not. Read that link I gave you on social anxiety and o get some advice from your GP.