You have correctly noted the causes. Being worried, not relaxing! easier said than done not to, but keep on hanging in there! Do you masterbate? this I am sure can help as you will find out what works for you. Get a nice small vibrator this may help. When you are with your boyfiend show him what you like. Help him by telling him and showing him as well. He would be a insensitive type if he wasnt turned on by this, and if he was not interested enough in you and to want to please you. Try also a good lube [not the sticky types] this may smooth the way for more pleasure from your sexual explorations. Hope this might help. I'm a guy, but I hope that I have some understanding .