Firstly, congratulations on starting university! Uni is a huge endeavour and it's important to focus on your studies and do the best you can. That is a priority, and you should not feel guilty or torn over dedicating time to that. Secondly, I want to add that it's not lazy to only do what you're capable of. You said yourself you're in pain and exhausted, I'm not surprised if at the end of the day you are not more active. Our brains need time to decompress just like our bodies, and scrolling on social media is a way to do both.
We are allowed to have hobbies and enjoy them!
Now. Habits. There is a technique called habit stacking which is where you use a current habit or behaviour and build another into that. Do you brush your teeth regularly? You could choose to add pouring out a libation of water to the gods while you brush (you're already at a water source after all). Do you like to sit in the shower and close your eyes, enjoying the water? You could say a quick word of praise or pray to the theoi while you do that ("Glorious theoi, givers of good things, thank you for your abundant blessings" etc.). As you walk to class is there a flowering plant or water feature, something that looks pretty and reminds you of their beauty? When you eat meals, could you portion off a piece first in offering to the gods? When we stop to think, there are a million moments in every day where we could add the gods to our lives, and you only need to pick one or two.
A reminder I needed too: you can ask the theoi for help in times of need. Attending university, you could pray to Athena, maybe Hermes, and/or any other gods relevant to your course. You could also pray to Apollo, Asklepios and Hygeia regarding your disabilities. This may help with the feeling of connection since it will be relating directly to things you live with every day.
I also want to try a little mindset shift here. Try not to focus so much on the idea that you need to build the habit of devotion, and instead focus on your love for the theoi. From "I have to find more time for this" to "I want to show them my appreciation." It's a small thing, but the stress of 'I have to I have to' really sucks out the joy. You are already accomplishing so much and should be proud of that, don’t be hard on yourself for one thing you’re not doing.
I hope my babble helped in some way. I encourage people to reblog or reply in the comments with any thoughts!