>>718470989
If you have a family. Research relatives and find through them new friends. It's easier if your relative shares same interests.
If you don't have a family. Search some hobby or something you can do with multiple people. With that you can try to build up some friendship.
If you don't want to touch grass. Search up online a group of interest that suits your interests. You don't even need to act like the nicest person.
If you want to reunite with old friends, just talk to them. Sometimes they think they got left out, that's why they fear to write an old friend a new message.
If having friends is not helping. Then you should consider getting a love partner and rather focus on your family. Just don't try dating apps.
Also improve your /fit/ and /int/ and then it should work. Also never have the feel you are left out, that's just in your head.