So I know I'm not the only one who has had this problem. I entered Ukpyr and was promptly attacked by everyone.
No problem, except I can't do missions for the general and can't get the grenade from him, which is game breaking. Killing him does not give it as a drop. The standard fix would be to gain the favor of a faction member, but the only one I can even start negotiating with is the black market guy in New City. He does not give a Spell option, so I can't us Charm on him. I gave him all my gold, about 50,000, and a bunch of items and he still attacks. My Diplomacy is over 30 which should be enough.

If I have to start over because of this I am going to scream, because there has been too much puzzling/running around fetching stuff to get to this point.

No idea what else to do

TIA

If a savegame editor can solve your issue at all, that would be dscheat.
I dont have it at hand right now, if it cant modify factions attitudes,
a hex editor can do the job by comparing saves where in best case scenario only the faction rating is different.

Assuming all saves have identical size,
create a save right before you can affect the rating of the desired faction,
e.g. in new game before you spek to a NPC of that faction.
Speak to it normal save a 2nd time,
then load 1st save and aggro it, save the 3rd time.
(the game may keep track on passed time, so try to do actions for saves 2 & 3 fast !)
Use hex editor (or [FC /B > myName.txt] at the command prompt)
to compare the 3 saves with each other to limit the results,
change values in copies of save to check the outcome in game until you get the desired effect,
and know the offset in saves for the specific faction rating.
Backup the actual save, load it into hex editor and adjust faction rating at the offset you found,
confirm in game that it works.

If saves have different size, the hex editor must be capable of resynchronizing compared files,
dont know any free stuff which can do that