How do I "start over" after "breaking up" with close friends?

I know, a lot of quotations. Sorry!

I know most people have close friends they can count on from childhood… people they can invite to tag along and introduce to others whenever they have some kind of event to attend (a birthday party, work party, cultural event, etc.) or when hanging out with new people.

For me, it was two friends I had since elementary school. We could always count on each other. Fast forward several years, into university. One of these friends became toxic (and pretty much always was, but until recently I had been too lonely and naive to know otherwise), so I dumped him. I do not speak with him anymore. It stunned him and our other friend.

Now I’m a more social girl and do not waste time with people who make me feel like shit anymore. I have some casual friends and acquaintances, but without any close friends to count on. I feel like at this age, it’s hard to make close, close friends anymore. That special bond of since-childhood friendships just can’t be created. I wish I hadn’t been so shy and socially anxious all those years… if only I knew then what I know now.

When I meet new people, sometimes they wonder if I want to ‘invite a friend’ to their social gathering…. but I have no one to invite. There’s no one I know well enough that will bear a social situation with me that may or may not be pleasant… does that make sense?

Ughh, sorry this is so long. BASICALLY, I am saying I have but one friend to go through the good and the bad with me. I know I am lucky to have even her, but… is it possible to make friends like this at my age? I’m 21.