A little bit of background which might help in appraising the situation. If you want to avoid the fluff, the actual concrete question in bold at the bottom.
Up until the start of April this year I've done a linear progression using more or less the Starting Strength model, with some of the typical shenanigans that Mark Rippetoe would not approve of. No powercleans (I can't for the life of me get into the rack position, not that interested in explosive power), added rows. Prior to that I had already done 1.5 years of strength training with very mediocre results, mostly due to a fear of regaining fat and not eating through plateaus. This time I ate like I meant it and the 6 month progress was better than everything before then. I wouldn't say it was a waste experience-wise, though.
Now the time has come to lose some of that excess fat, so since the start of April I've introduced a caloric deficit. I'm lowering the calories from week to week rather than directly plummeting to some bottom value, since this is easier to maintain for the planned 12-or-so weeks and seems to avoid the typical weight loss stalls. Regardless of whether I'm right, it seems to work and losing weight is currently easy.
Unfortunately, for the past few weeks my motivation to do my workouts has taken a nosedive. I find myself making mental excuses, such as "I'll go to sleep early and get more time for it tomorrow" or go to check some Stack Overflow questions on my laptop and stick around until it seems too late to still go to the gym. I've maintained a rather consistent gym discipline for two years, apart from the occasional bad week, and usually enjoyed my workouts despite self-doubt and grinding through some exercises. So I'm not sure why things have taken this turn.
Some reasons I can think of:
- I've had a clear goal for half a year (get stronger no matter what) and now that this goal shifts (lose weight, maintain strength) I'm a bit directionless.
- I'm anxious about a workout going "badly" compared to previous ones because some loss of strength is inevitable with a caloric deficit.
- I've grown tired of doing the same workouts and exercises (squat, deadlift, bench, overhead press, rows, chin-ups) all the time.
- The idea of squatting 3 times a week and every time having to give it my best down to the last rep has burned me out (me and the squat aren't on the best terms).
If after a prolonged and successful period of working out there's a sudden lack of desire to continue, what is likely the most important factor? What change would turn things around?