What would you think of going to where people have interests like yours, and/or trying some new interests out? For example, volunteering at a place where there are other volunteers; trying out/starting again with a sport/craft/hobby and joining an appropriate club/team etc; getting involved in politics, helping out the campaign (national or state or local) of someone you support and believe in; joining a book club if there are people your age involved; getting active in a church/synagogue/mosque (e.g. "Theology on Tap" is aimed at young adult Catholics); taking a class.