It's tricky to tell at that age, as they do get hormone bursts that can make them emotional. But I would like to advise (a bit) on 11+ prep. It really doesn't need to be stressful. In fact, it shouldn't be. the work should not be onerous at all, if he is up to it.
Both my DC did 1 paper a week - so one comprehension, one maths, one NVR and one VR each per month, plus one essay or story a month, over about 14-16 months. And we'd go over mistakes. So it was a total of about 2-3 hours work per week. Imo, more than that is too much. It's counterproductive because they get stressed and anxious and then underperform.
As the exam drew closer we got some of those 10 minute a day papers and did those about 4-6 times a week, but only for 10 mins, never more, just so they could stay fresh on the weaker things. And we read to them every night for about 20 mins, and chatted about comprehension, made note of words they didn't know, but very casually, so it felt like a bedtime story, not work.
We made sure that every single weekend we were outside, running around for at least 3 hours, and that we had at least one fun activity lined up each weekend. That way, if they thought they were getting stressed over 11+prep, we could say, 'Yes you work hard, but we also went to the cinema with your friends and out for pizza with granny (or whatever) and built dens in the woods/went sledging' etc. So they could focus on the relaxing stuff and realised life wasn't just a slog. It's one of the few things I feel I got right for them. They both passed every exam for every school and neither of them got too stressed about it, despite one of them being prone to anxiety generally.
So, I suggest you focus on the fun stuff, make sure some is planned each week, and just be very light about the 11+ prep. I always used to say: one hour of this, then you have three hours of gaming/Lego/football with your friends, so they realised they weren't being overworked.