Male 23. eye power before left (minus 1.5 spherical) right (minus 1.75 spherical) currently left (minus 2 spherical + 0.50 cylindrical) right (minus 2.50 spherical + 0.50 cylindrical) why power increasing fast in just 8 months. when stabilize ?

Refractive error change in 8 months is not unusual. The change will slow down with age. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV and Covid vaccines. Wish you good health!

It is possible that your glasses prescription power changed that much in 8 months, but more likely there is a difference in the measurement process, or you may have had a slight focus spasm from looking at your smart phone. A measurement taken after cycloplegic eye drops would tell you which it is. Prescriptions usually stabilize by age 26.