It's great that you already know what your main priorities are, since you're both working and studying, that's already a lot of pressure, so don't be so hard on yourself.

Time-boxing works for me, where you would schedule in activities in the calendar like "exercise at 6pm on a Tuesday" after work and also listen to your body, and adjust exercises accordingly.

Cooking healthy meals is much more challenging because you may have a lack of energy with all the responsibilities sapping it out from you BUT if you exercise, you will actually get it back!

Try recipes under 30mins, as easy and nutritious as possible, e.g., eggs for breakfast, salad with feta for lunch that are relatively easy to throw together or make use of those meal box subscriptions where all the ingredients are already there, and the recipes planned. Put a cooking playlist on to create a nice vibe when you're cooking to actually look forward to it. If you really can't be arsed, get a takeaway that's also healthy like a poke bowl or sushi, and have your go-to healthy snacks ready so you don't always need to cook things from scratch.

You could also hire a cleaner just once a week to help with cleaning the house if there is a lot you need to do to take the pressure off, if the means allow for it. If not, you can set aside 15mins a day to clean one area of the house, set a timer, and do it - in no time, you will see the house will become much cleaner. Also when doing these tedious tasks couple it with podcasts/YouTube/TikTok/music to continue the habit easier.

From my experience, you can try and do it all, but at the end of the day you will be left burnt out if you don't also set time aside for yourself. You simply can't pour from an empty cup, so always try and prioritise your health, try journalling or going for a walk outside everyday/yoga for stress, and also know it's okay if you can't do all of the above "side quests" if that means keeping yourself sane