(1) Is this caused by the same Bacteria as from when I had it a few years ago?

Possibly so. The trouble is most doctors will treat with antibiotics anyway, regardless if any infecting organism is found or not.
(2) Did I get this from a girl?

While Epididymitis may be caused by an STD ( Gonorrhea and Chlamydia ) are the two of note, most cases are not sexually transmitted.
(3) What is the success rate of it going away/ or me always having this?
I simply don't know the true answer to that. It follows that those of us here ( and we probably represent the tip of the iceberg )for the most part, have suffered quite a while. The picture may be blurred, there may be cases of guys suffering for a few months, then recovering and that's the end of the matter for them.