Given your most recent workout was traumatic with the back spasm, I don't think that its very surprising that you had a fail with your squats. Did you actually complete your 3x5 at 195? If not, protocol is to repeat that weight, not increase. Same with your press. Also, what was your last load for press, 80? If the 5 lb jumps are difficult, you should be microloading, increasing by 2-3 lbs. Your reason 2) is probably the most frequent cause for failure, assuming recovery (sleep, nutrition, time) appears adequate. Failing is something that affects everyone, its part of the process. Given this is your first failure, I recommend that you keep on with the program, you may get all your reps next time. Also, fear is not good, and if you are tentative because of your recent back tweak, you might back off 5% to 10% and work back up to rebuild your confidence.
All that said, we older folks don't necessarily benefit from grinding away at near max weights for extended periods. If you really feel that you've eked out as much progress as possible on this program, it may be time to change. Do you have Practical Programming 3? Andy Baker's program for master's intermediates may work well for you (see p. 233).