I had few friends growing up, I was pretty low on the totem pole at school, but for much of my 20s (damn I feel old writing this...) I had no friends, no job, no money and the loneliness was palpable. Having only 1 friend can be a little lonely but zero is a whole different feeling.
The problem is that people somehow smell loneliness and stay far away. That always struck me as unfair.
All I can say is to use this time to develop hobbies like I did. If you want to make friends, develop yourself. Varied hobbies and skills make you more interesting to new people. I tried 3D computer graphic design, wood carving, DIY projects, computer programming, I wrote some music and poems, I learned climbing, archery, drawing....
I don't do them anymore, but they are talking points, conversational hooks, and a shared hobby is always a good start to a friendship. (They also happen to be some useful skills if they ever come up.)