[Kumagoro]

Well, for me it was always nerves and paranoia. Thinking someone would hear me or walk in, that's never very relaxing. Lock your door and do it when no-one else is at home. Take it slowly and don't panic if it doesn't feel good to begin with. Just try your best to enjoy it at a pace you're comfortable with. Masturbation is about finding what you find pleasurable. There's no right or wrong, so go with whatever feels good, don't be afraid to experiment. Over time it should become a more enjoyable experience, and therefore less painful. You shouldn't be under any pressure to enjoy it "just because", as that won't help you relax. Go with the flow.