> Everything feels hollow now.

I'm slightly younger than you are but I remember how video games and sitting in front of my computer made me feel like this. You asked how to be willing to be alone but I will pivot my answer here that maybe you don't have to be alone? If you don't want to be alone here are the steps I would take nowadays.

I would recommend finding a improv class. This helps you to get used to laugh to yourself and make a fool of yourself. Also the people attending improv classes are more open in general. When you are more comfortable with these feelings then it becomes easier to open up a conversation with strangers. First times it feels awkward but you can frame the narrative that this is just you learning social skills and your body adapting to the new situation. When you do this enough it becomes easier to find new people into your life. You might feel creepy and they might feel that you're creepy but it becomes easier when you practice. Be open about your learning: "Sorry if I'm bothering you. I'm trying to learn how to speak to others. How is your day going?"

If the chit-chat goes well ask them for coffee or a lunch or if they want to join you for a walk with your dog. Strangers often ask if they can pet my dog when walking in the public with her. Put your focus into them rather than your feelings. Ask how their day has been. Ask how do they spend their time. Ask follow up questions: "Oh you like knitting? It reminds me of my Grandma. Are your granparents still alive? How often do you see them?". This way other people feel that you are actually paying attention and it helps you to connect with them.

Read also this one: https://www.experimental-history.com/p/good-conversations-ha...

Learn how to use your calendar and start planning stuff together with the people you meet. Most of the people are just self-centered and want to have someone who would listen to them. If you provide this for them you will find people who are interested in your company. Hopefully eventually you will meet also few people who will listen to you as well.

When you start having more friends/acquaintances the hollow feeling did go away for me. The hollow feeling still comes every now and then but I've somehow accidentally built a routine that when it comes I will reach my phone and suggest something to do for my friends.

YMMV but for me it has been a long journey but definitely worth it and doable for others if they can endure the anxiety during the way. Also remember to sleep/eat/excercise in addition like others said. When you don't everything else falls apart.