I was in a similar place a few years ago. I'll just list what worked for me, so it's not assuming you don't do any of this currently.

But firstly, know that things will get better over time. You need time to get through all the emotions, the new environment, the new way of life. I didn't know it at the time, but looking back at it, I wish I had this on my mind each day to just eke out any bit of positivity I could.

But the five main things I changed in my life to get me to feel better: 1. Lift weights. I didn't necessarily go to a gym, so there was no additional social aspect from this, so doing so would probably help. But I bought some gym gear and worked out at home religiously. Had a plan, tracked it on a spreadsheet, and measured and reviewed progress every two weeks. Really helped with the confidence, and there's a lot of research that shows exercise is good for mood and depression.

2. Walk everyday - ideally outside in the sun. I got up early, went for a walk so that I caught the sunrise during it. This was probably one of the biggest changes I made that improved my mood and wellbeing, that I continue to do it religiously today.

3. Learn a new skill. For me that was 3d modelling. Just having something new to do, and tracking progress, really helped with my self confidence. Though if you're not in the habit of lifting, you could combine this and [1] if you're learning to lift.

4. Changed my diet. This was a natural change from lifting. Eating whole foods, and reduced the junk (still enjoyed some pizza/fried chicken on weekends), but otherwise it was healthy foods during the week.

5. Volunteering. Sometimes at a food bank to feed the homeless, and sometimes helping a local group who was in charge of restoration of a creek which required cleaning/tree planting etc. It's amazing what doing something for others does for yourself.

Things will get better for you - no doubt!