I didn't get my driver's license until I was 23.
I graduated high school in 2000 and didn't make any friends afterward. In fact, I don't have any friends, just work related acquaintances.
I didn't get my first job until I was almost 22. That job lasted 1.5 years. I was unemployed for the better part of the next 2-3 years.
I'm 28, socially I often feel like an awkward 12 year old. I've never had a girlfriend (long distance online thing doesn't really count IMO), never been on a date.
Trust me, it's never as bad as it seems. Feeling like a loser, and being a loser are two entirely different things. You are not a loser. We all have different paces at which we develop. Tackle one thing at a time, trust me...it is much less overwhelming that way. And above all things, remember that God loves you. As strange as this may sound, He created you the way you are. In His eyes, you are precious. When God looks at you He sees His beautiful creation. When you hurt, He hurts.
When I was fully able to accept who I am and all my limitations and realize that God loves me more than I could ever imagine, everything changed. I still struggle with anxiety and I do have my moments of complete frustration when it hurts beyond words to be this way...BUT there's no downward spiral into depression. There's no more being miserable for days. I don't know why God does what He does...it is confusing sometimes to think that such a loving God would place a such a burden on His beloved children...it's complicated and none of us really have any concrete answers. If I didn't have anxiety, I might not have come to God as I have now. Maybe my anxiety is a gift so I could come closer to Him. I guess what I'm trying to say is at the end of the day God's love, mercy, and peace enables us to better handle the difficulties we face. God bless.