I want to have sex with my girlfriend

You are addicted to masturbation if it interferes with your relationships and has a negative impact on your life. Some people need more sexual release than others so how often you masturbate is not an indication of addiction.

To ask your girlfriend outright to have sex is not a good idea. Girls definitely do not like this as it makes them feel that you are only interested in sex and not in them as a person. She might have moral objections to pre-marital sex and she will be offended that you ask her for sex without knowing what her view about this issue is. Sex is a very sensitive issue. When the two of you are alone, tell her there is something you want to ask her and that you would appreciate it if she could be completely honest in her answer. Say you want to know how she FEELS about sex. Respect whatever her she says. Do not force her to have sex or be upset by her answer.

Take it easy.