I would suggest to spend nights together in bed and watch movies. Then kiss and escalate. After few nights you could be comfortable having sex. Really think you should do little things than couples do. Life is short so eat dessert first. If you want to be his gf then act like you already are. Stay close to him and use situations where you can be together. Find those gaps. For example my sucsess with girls are mostly my warrior soul of not giving up.
Hes weak and unsure. Use his doubt and make him sure about you. Be a woman that he needs - be good to guy and do some things for him, say some nice words. A little love can go long way. Confess your feelings and he will respect you more for courage and look more serious at yiu.
Doubt kills more dreams than failure ever will