Jealousy is an emotion that can be very damaging to ANY relationship. It can also prevent you from growing emotionally. It is not the same thing as envy. Jealousy wants what someone else has. Envy is when you don't want someone else to have what you don't have. If a person is jealous, they already have what is desired but they are afraid of losing it.
When you are feeling jealous, you are undergoing an emotional combination of anger, dependency, hurt, and self doubt. When you spend time focusing on what you are not, this is a result of insecurity.
Sometimes when we are afraid of losing something, we actually cause it to happen because of our actions and behaviors. All our thoughts and actions are centered around our fears and insecurities. This causes more fear and insecurity. These feelings cause other harmful feelings and may result in us indulging in self pity.
Sometimes you need to think why are you getting jealous? When you have the person next to you or maybe away from you for sometime but comes home to you later on, then you still becomes jealous, that is actually not jealousy but envy. Jealousy does not make you more angry than envy. So stop being jealous and take friendship one day at a time so it doesn't hurt yourself.