4L60E no reverse
I suspect your don't actually have 2nd gear and the high RPM is caused by the delay to reach the MPH for the shift into 3rd.
With a broken Sun Shell you lose Reverse, 2nd and 4th.
Unfortunately the converter then also needs to be replace or at least opened, cleaned and welded back together. And any aftermarket cooler is best replaced too after throughly cleaning the cooling lines. Sorry for all this bad news.
However, since the damage is already done and you have since driven it a bit, driving it some more (easily!) probably won't increase the damage level.








