At your age, expect your distant vision to change some over the next few years, then it it should stabilize by age 30 and remain stable for decades. After age 40 your near vision may change, requiring bifocals. This is all normal and not a problem for airline pilots.

Note: Your refractive error looks close to 20/100. If you cannot see 20/100 or better WITHOUT correction in each eye, a few US airlines might not hire you, and most foriegn airlines won't either. The 20/100 used to be the FAA requirement (dropped 10 years ago), and a few US airlines still require it. I would expect most or all US carriers to drop this requirement as time passes (and people sue them). At your age, it shouldn't affect you unless you want to work for a foriegn carrier.

Regarding diabetes, the medical establishment has come to the conclusion that most adult-onset diabetes can be prevented by diet and exercise. My father had exactly this experience, lost a bunch of weight, improved the diet (still drinks) and his blood sugar is just fine now. You should probably research it, and evaluate your lifestyle to decide what your risks are and what you can do about it.