The boundary setting and leaving statements might not be best at this point, better to make a plan and know what you are going to do and not alert him in such a manner that results in him acting out...please discuss this with the experienced DV people...we have alot of collective experience here and resources to share, but professional advise is better tuned to you, your situation, the area and laws where you live and your options.
You can do this! Ask any of us if we wished we had done it sooner....my answer is a resounding yes!