The hanger is bent, or possibly the whole dropout. You can bend it back, carefully, with a big adjustable spanner. Be very careful to get it straight and not to adjust the rear spacing or the angle of the dropouts.
There's not much point in taking it to a mechanic - you're no more likely to snap it off than they are. The only difference is that they might have a jig to ensure that the derailleur hanger is in precisely the right position.
If it snaps, it snaps - unlikely, though, and you can always get it repaired by a mechanic.
The hanger is bent, or possibly the whole dropout. You can bend it back, carefully, with a big adjustable spanner. Be very careful to get it straight and not to adjust the rear spacing or the angle of the dropouts.
There's not much point in taking it to a mechanic - you're no more likely to snap it off than they are. The only difference is that they might have a jig to ensure that the derailleur hanger is in precisely the right position.
If it snaps, it snaps - unlikely, though, and you can always get it repaired by a mechanic.