I can really relate to your question. I have had similar decisions to make. One of my big character defects is procrastination, so I don't like to be pinned down to one answer if I still have indecision.
This last time we decided to live together again. It was really him pushing to come back "home". I made and have stuck to some boundaries this time. I decided that I was ready to try reconciliation, but if he crossed my boundaries then it was time for him to leave or to renegotiate the boundary.
I have trouble with the black and white thinking too.
One thing I've tried to ask myself is: Is this a good decision for today? I reserve the right to change my mind tomorrow. What do I want to do today?
I do know that the answer is there for you. You already know what it is you'd like to do.
Also you can put the decision off by simply stating that: I'm not ready to make a decision right now. Sometimes it helps to stay in the present and just make a decision for this day. I hope this helps.
I'm confident that you will make the best decision whatever you choose!