hi, get your glasses number checked by ophthalmologist and not buy directly from optician as you may be using overcorrected number and hence getting blurring for near work. as you have mentioned you are a student also avoid screen time for more than 2hrs without a break, it leads to dryness of eyes.
Next Steps
start refresh tears eye drops one drop 3 to 4 times a day for a month. get retina checkup done as you are a myope to rule out any retinal thinning as you have floaters or black spots
Health Tips
avoid lifting heavy weights, reduce screen time