Loneliness at an adult

As an adult that didn’t get married or have children and only has two living family members, I find myself feeling lonely and without deep relationships. I have friends, co-workers, and acquaintances, but no best friend, that go-to person, the one who has your back, will listen to you when you cry and laught with you when you celebrate. Someone who cheers you on. The person you can call at any time of the day. It’s hard to meet and develop deep relationships as an adult. The people in my life are wonderful, but I don’t feel I can be vulnerable with them.