I don't think that's the case, like going through your merit giving activity, you're like a teacher in this Forum that always push members to get on their feet whenever they're slowly dropping their efforts to give the Forum quality post. And you're well known to give out merit by reviewing posts that deserves it not like you wake up one morning and start giving merit to post that's not close to receiving any merit, you know how to do your thing and I believe you're more popular than the other merit source.
And again, you can't tell in any way that you're giving alt account merit, you're not from the spirit world to know who's who, you do what you have to do without minding if you're giving alts some merit, believe me that if you start thinking that way, this journey of post review will come to an end, you'll stop doing the merit review because you feel you're giving alt account merit.
Long or short slump it doesn't matter, you also need a time out to cool down a bit before coming back to start up from where you left it. Everyone have some other things to do outside the Forum that's why we get to see some account being inactive for long, so I'd say take your time in handling your stuff before coming back (which you have, I suppose) stronger.