Welcome to SB, and longer term the sport!
All the advice so far is solid.
Fear/Flight is normal response but as you've already dove, with sharks no less, the hard part is over.
Reading the Accident Reports is like a getting your news from a single source... CNN/FOX ;-)
I too started by reading them and still do, but rather than "OMG that will happen to me" approach its "So that's how I avoid an issue"
Honestly, just stop reading them until after your 50th dive or your really comfortable in the water.
As to the two items you point out as your mistakes: Rapid accent and blowing through the safety stop.
1) *shrug* Rapid accents are common, too common, yet most never have noticable problems.
The key here to make sure your never holding your breath...
Just doing something that's kept you alive since the day you were born: inhale, exhale, inhale, exhale...
Btw, if you'd been going way too fast the DM probably would have controlled your ascent rate for you.
2) Safety Stop's are not Deco Stop's. This forum is wrong place for a full discussion just remember there is a big difference, and blowing past a deco stop is a LOT worse.
Finally,
The course work focuses on what can go wrong and teaches you to identify and deal with the issues rationally. Ascents/Desents, Surface Tows, Emergency Ascents, Air-Sharing.... it's enough to scare anybody, relax... it's learning to walk, if I knew then how many times I'd scrape my knees, bumb my head, or break a bone I'd have stayed in my crib!