yes the happiness u feel when u are alone is called momentary relief. Its an ex of short time happiness. But in the long run u can be more happy and satisfied when u develop good emotional connect with ur family members and friends. Like people who drink cigarettes feel very happy when they do so but in the long run it may destroy their lungs. u enjoy being alone right but u might not enjoy it in the long run. So it would better off to treat this habit of mood swings. Would suggest u to be serious about this problem and learn to interact more with people especially when u feel low or left alone. If u are not able to help urself take some proffessional help.