More effective separation of lesson plans for all 3 preps

One area where I would like to grow and improve as a teacher this semester is to find a way/ways  to create engaging lesson plans for ALL 3 preps for the therapeutic services pathway for healthcare. I have been successful in separating the courses, however, I have not been able to provide as many differentiated assignments as I would like to due to time constraints, limited access to textbooks, and the copier in the main office. I find it difficult to get all of my planning done in the time that is allotted for planning at school and the added time staying late in the evenings. The way that my classes are arranged requires that I change the white board or lab area between class changes and that is virtually impossible because all teachers must be at our doorways to monitor students during transitions. I generally use my planning period as well as my lunch period to prepare for the upcoming class(es). I rarely get a chance to plan a week or two in advance just because of everything that I need to get done. I find myself trying to do lesson plans on the weekly most of the time which is difficult because of things I am required to do at home. I started NTI out of sequence, however I hear that during the summer semester we have to create a large number of lesson plans. I look forward to that time so that I may be better organized and prepared for next school year. I feel as if I am doing a better job than I did last school year after I was hired 8 weeks into the semester and taught all of my classes mostly the same concepts during the first semester. This year I have been able to completely separate the three preps but it has been very taxing. I absolutely love teaching healthcare science, I just look forward to the days I can do it more efficiently.