all-around persistent pain or tightness?

hello !! for a bit of reference about me, i'm a 19 year old female, 5'1" 🙂

i haven't had the best physical health admittedly - and i do lack a bit in exercise (and vitamin D) at times as i'm currently in a situation where i'm not allowed to leave my house outside of a few times a month to go to the store, even for walks

which means i end up sitting at my computer for up to 18 hours every day - with a minimum of at least 10

recently, i've been experiencing on and off sharp pains all around my body, it was first in my inner right elbow for a good while until i was able to keep it in a position at my desk where it was straightened, and since then i haven't had as much pain while i use it! it does come back on occasion though ...

now, i've been dealing with sharp pain specifically in the back of my left calf, my right shoulder on occasion, sharp pain in both my ankles, and in the area of my arm just below the elbow - and if not sharp pain, then it's definitely a dull pain that doesn't really disturb me - but i can definitely still feel it

i used to have knee pains that lasted overnight, but i stopped sleeping mostly curled up and started uncurling and straightening my knees again which ive noticed has helped a lot 😀

some of it feels as if it's simply strained muscles and i was mostly wondering if anyone has any exercises they recommend that focus on these specific muscles to ensure that they're not as tight or hurting, especially for prolonged computer use! or even just any tips if they've suffered similar pain 🙂