Maytag Plus SxS, does not cool on frig side/barely freezes on freezer side. What is wrong?

About 2 months ago, same problem, so we unplugged it, cleaned it out, pulled away from the wall, vacuumed back, and found on the frige side behind the crisper, rock hard frozen coils. Used a blow dryer to thaw the coils, then put it back together, plugged it in and turned set the controls to 1 or under for both sides. Behold, not only did it start cooling again, it actually made ice (had stopped making ice gradually from full ice cubes to hollow ice chips, to no ice at all). Two days ago, found freezer not keeping things fully frozen, stopped making ice, and again last night figured out the frige was not cold either. Yes there is frost on the bottom of the freezer, lights work, and can hear compressor/fan motor (humm). What is the problem? Where can I get parts? Is it hard to install?