When I went through various losses in the past, I wish I had known about the law of attraction, affirmations, things of that nature - I felt so lost and physically about the same as you are describing. This is some of how I've learned how to deal with things since then, I hope it helps!

1. I threw myself into my work and personal hobbies and interest so that I could distract myself. Okay, driving an Uber isn't super intellectually distracting, but maybe you can listen to a podcast, try and learn a new language, or listen to youtube videos / documentaries about something you love to learn about or something which can be beneficial to your future (hopefully you don't get a lot of people who are annoying and want to have a conversation lol).

2. Set aside some self care time where you allow yourself to feel things and just be sad, nothing else. Light a candle, lay down, stare at the ceiling, cry, then think about the reasons you're sad, process it, and change it to something positive (for example, "I'm sad that I have to sleep alone" - "that's okay, because now I am creating physical and mental space for someone that truly can care for me in the way I want to be cared for).

3. Create new routines that make sense for you and provide comfort through a different ritual, and make sure to reward yourself somehow for getting through the day

Hope you feel better soon, but time is the true answer. Best wishes in your studies and healing.