This is all brand new to you. Its no wonder you are having a hard time adjusting. No one would be able to at such a short notice. Give it time, let it evolve, don't rush, communicate often and honestly and it will be fine, whatever happens. There is no rush.
I would suggest haulting plans for a wedding if you are in the midst of that and plan instead what you are all going to do if this isn't going to work out. It is extremely fast to have a lover move in, some boundaries and ideas about what will happen if it doesn't work for one or all of you would be a good idea I think. When shit hits the fan, we all need somewhere to duck to. Not that it will for you all, but preparing for that before hand will make things easier if it does.
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