1st of all, you have no obligation to him, he has no authority over you, so do not allow him any influence over your decisions. if you do not want to go to the meetings, or any other jw activities, just tell him so. 'sorry, i understand this is something big for you, but i have lost interest' or similar. i tried it, and it works.
2nd, every single point he might being out can be debunked, with the bible. even if you are not up to the task, he still has no real point. are we living in the time of the end¿ according to their own understanding, the time of the end is already going on for 140 years, and no sign of the end yet. do we have to go from door to door¿. taking a look in the kingdom interlinear learns us that 1, nor Jesus, nor his apostles, nor Paul ever went from door to door. 2 the only place where 'from house to house' is mentioned, literary says ' do NOT go from house to house', a command from ... jesus.
so there is no reason at all you should feel intimidated