Best of luck to you!
I have never been lucky enough to visit Ireland, so have no idea of Donegal, but I'd hope you could connect with an ex-pat community, perhaps of Facebook or Reddit, and make some connections before leaving.
Will you sell all that you have and purchase new when you arrive?
Can you hire someone to help you with the legal issues? There is a site I've looked at, https://www.taxesforexpats.com/, that might at least be a start.
And can you hire someone as a liaison for helping you get established while there? Would you need to make more than one trip, like to suss out where to live, or can you just put yourself in the hands of someone who does this for a living?
Again, just want to wish you luck. It likely won't be the easiest thing, but the peace you will have will be worth it. 
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