Also, consider solicitor? start getting yourself protected, putting down boundaries, securing maintenance and other essentials.
Don't take casual calls from him, have days and times, e.g. phone fridays at 6, if the girls want to speak with you they will answer the phone...would want solid dates for contact as well, you can't have him waltzing in and out as and when, trampling over your good work.
Revert to emails as preferred contact, keep asking for everything in writing. Get the ball rolling with maintenance. / car.
Take care of number one ( and 2,3 & 4 )