Here as long as you continue, and happy to ensure a 48hr turnaround on any of your posts. I am sorry you are feeling despondent over this. I think it's perfectly okay if you'd like to suspend it indefinitely. Three brief thoughts:
1. puzzles are hard to do in PBP because everyone is afraid of committing others At a table, somoene would suggest something and it would be shouted down or whatever; here, though, we are stuck but also not wanting to step on each others' toes. That's not yourfault at all, just part of the medium.
2. In half a year we're all going to want to be rolling up new characters anyways, and I think many will lose interest in older games. That suggests to me now is NOT the time to start a new game, unless it were self-conscioulsy designed to be very short and fast.
3. Finally, though, I think I want to insist that this is your call. You do an incredible amount of work, and we are the benficiaries and recipients of your kindness. Yes, it is collaborative, but I am under no illusions about this point and the balance of effort and commitment. I like your games, and I want you to be engaged and excited for them. If these aren't providing that for you, I think it's perfectly okay to let them go.
And, once we have a new PHB, I will have a million new things I will want to play.