Your equipment has probably grown to what it will be. But that's anatomy. Many men report that their libido maxes out several years later (typically between 18 and 25) regardless of when "puberty" started.
We think of "puberty" as the change from boy to teenager, getting erections and ejaculation, and then it's done, but it is really a longer process. Your body will develop and adjust to the incoming hormone flows over several years (just see how long it takes people to outgrow getting pimples). It will also be sensitive to your health. Slightly larger erections and more penile sensitivity might simply match general health that is better, or a body in better balance than before.
Maybe some. Your hormones may be shifting . . . hello testosterone. Try to go with the flow as you will probably be like the rest of us with shifting hormones and things for the rest of our years.