First, glad you are OK and not hurt!
As jdc1 mentioned, tossing enough money at the problem most anything can be repaired.
The problem however it may cost more than the value of the trailer, not to mention there could be other hidden issues like bent frame, damaged or bent axle that may not be as obvious until you try to tow it.
While it is possible to repair the fiberglass with a boat cloth patch and resin it is not an easy or quick repair especially if you want the repair to 100% blend into the original fiberglass surface plus would require additional sanding, priming and painting.
It might be possible to send the trailer back to the factory and have them remove and replace the entire cracked wall which may be cheaper than paying a fiberglass body tech and then paint techs plus paint and materials.
I think you may be further ahead to let the insurance company decide whether to scrap or repair, after all they will be footing the bill either way.
As far as not having WD connected, that may have saved you from rolling your vehicle over also and I highly doubt that WD would have prevented the trailer from rolling.
Chalk it up to a newbe mistake, making tight turns under hard acceleration or high speeds as you have found out can cause high profile items like TT to tip over. This is especially worse if the hard turn is on a hill which puts the TT into a tilt.
I have a turn across traffic that I have to make coming down a 11% grade and the stop light and left turn is near the bottom of the hill.. I take that turn very slowly, I am sure there have been lots of folks behind me shouting unmentionable words. Even as a well seasoned towing veteran, that turn gives me the pucker factor every time.
Whenever you are towing, you have to be far more cautious and aware of this potential issue. You can't be in a hurry and the correct thing most likely would have been to have stopped as best as possible or just coasting through (provided no oncoming traffic coming towards you) instead of giving it gas and darting across.