Don't think i have ever picked up a weedeater at the trigger point, it's always been picked up by the shaft tube in front of the handle housings. Idk why, but i have always done that. I guess it's like a balance point to lift the whole thing. In a few days, you'll forget it hurts. Putting like cortizon 10 on will help heal faster an take some of the sting out of it.
Good thing you had on long pants, and substantial material to boot.
Imagine how much worse it would have been if you would have been in shorts.
I see people every year mowing/weed eating in shorts and flip-flops.
I just shake my head every time.