A lot of people who feel lonely, are hardly ever alone. imagine how shitty and uninterested we really are to eachother and ourselves... if we can be together and feel alone at the same time. Stop neglecting yourself, and that will make you stop neglecting others.
My tips: Actively take time for yourself. to get to know yourself and become more aware of yourself. Even if you do not suffer from such symptoms yet, it will be one of the most valuable things you can do for yourself in whatever position or situation you find yourself.