I have the solution. It's what my dad's trailer does on his old Terry bass boat.
Cut the trailer just past the roller (on the bunk side, not hitch side). You'll need to weld an extension to the back part so that it 'lays' over the front part, then drill a hole through both sides.
The concept is that the trailer will "fold"....scissors-like. You use a hitch pin to lock it in place during trailering. That way, the back will "flip up" when you launch and load, without putting any pressure on the hitch.
This allows you to launch in very shallow water, undeveloped banks, and other tricky launch situations. Works great!
I couldn't find a pic of it online, but I'll be at my dad's this weekend and take a pic of it.