Ca'nt get to sleep without jerking off. Is this an addiction?

It's not addiction. in the usual sense, and it may not be an issue at all. Many people have high levels of sexual tension, and this may be normal for them. Other people can only achieve release through masturbation, rather than physical contact with other human beings, and this may well be a problem. If it is interfering with your life, making you feel guilty or otherwise bothering you, see a therapist about it.