A lot of people pride themselves about being able to stay alone but mankind wasn't made to live alone. No one is an island. You might want to be alone once awhile or most often, but always is never good. There is a difference between being alone and being lonely.

Source

If your loneliness isn't because that's what you would choose, but because you don't have people you think care enough or understand you enough to be with. Being alone helps you reflect and get to know yourself better, but too much of everything is bad.

Lonely people have more health problems, and they perceive the world to be threatening. People are in groups this days but feel disconnected from everyone. People can be in relationships and yet feel distant from their partners.

Open up yourself and reach out to people. Hurt and pain is what makes life interesting and if you prefer not to reach out to being hurt, then you've never lived. You are just existing. There's always someone who needs a friend. Be a friend, and you will make one.