I believe if it were mine I would bring it in to a place that repairs axles and springs on heavy trucks and get their opinion.
They have the expertise to at least see maybe what caused it in the first place and could reccomend neccessary repairs. Then depending on what they told me I might try to tackle the job myself or just have them do it.
I don't know that you have to be brilliant to get it realigned and straight again. But you would have to willing to tackle some big, possibly rusted bolts etc. and either have a hydraulic press to straighten the axle or be able to weld in something new.