If you don't have any sexual desire with this new bf, maybe you just aren't close enough yet. Especially at your young age, all relationships don't have to have sexual desire as a component. It's ok to be just boyfriends without wanting sex. It's just a step through your long path of life. There are many levels of intimacy and they don't all include sex or sexual desire. Maybe your inner self is holding your sexual desire for the one person that it's really right for and that person has not appeared (or reappeared) yet. If you care about your bf, spend time with him, show him you care about him and frankly at your age your showing respect for him and you by not having sex. Give it time, trust your mind and heart and body to know when it's right. Keep talking to your t and reaching out.