College is hefty on one's time, and I understand creator's block / drought of ideas. Please do take your time, S.I.T is an amazing game on its own. The DeCline DLC will be great and I am positive of that, but it won't be worth it if it's at your expense.
If you have to scrap DeCline in the end, too, I just want to be sure you're happy with your own end product. As I already said, S.I.T is already an amazing (and completed) game, and it's got so many secrets as is. If people truly want what the DLC would have been (or so I imagine what it would have been), fan art and fanfiction, etc. are very common and there are other skilled creators.~
As that's been stated, have you considered a larger team being built? I know compensation is a (very valid) concern of yours, but I'm sure people would be willing to draw out a game plan with you and hear you out before hopping on and just demanding money from you. Just ideas. Either way, like I said. S.I.T is beautiful, wonderful, I enjoyed it as is. You did great, and no sweat on this, okay? <3 Please take care.