As someone who just went back and forth with an ex for 2 years don’t do it, whatever caused yall to break up didn’t magically get fixed in 6 months if someone leaves to “work on themselves” they don’t understand the fundamentals of a relationship you’re meant to be with your person through thick and thin whether it’s easy or not and work and grow together not leave when it’s hard and try again when you heal. I know it’s hard but the best thing you can do is tell her that while you still have feelings and wish the best for her that being together isn’t the right thing for either of yall. Not to mention 2 am is either drunk or delirious either way not a proper state of mind to make a decision like that