I think it may be too late for assistantships. I got accepted into Missouri-St. Louis but unfortunately it was a last minute application. They have a March 1 submission deadline and I panicked, needing one more safety school after getting several rejections. I even wrote an entirely new short story that I finished the last week of February, figuring that after the rejections that I needed some new material (my previous submission to the other programs had been the opening chapter of a novel). I took a chance and it worked! They loved the story and three weeks after my last minute submission I got accepted. However, as I was rushing things (I even had to email the director a corrected draft after the deadline because of typos, which he graciously accepted), I overlooked the assistantship application. The director told me that they had already made all the assistantship offers, but that if anyone declined, I was on the waitlist for any openings.
I think I may have to wait out this year then, work and save $$ because even with a stipend it's very hard to make ends meet as a grad student. I'm also on the waitlist at McNeese and they told me something similar as St. Louis, that there was a possibility of letting me in without an assistantship if I don't get off the waitlist (it's a very small program). I wrote McNeese back and explained that it doesn't make sense to go into debt for an MFA program, and asked about my chances for next year since I'd been accepted this year already. Frankly, sinking money into a writing program makes zero sense from any financial returns perspective, given how little money even successful writers make. You'll have to take a second job most likely, anyway.
The lesson for me is to be more aware of what most programs are looking for: polished stories with a clear narrative arc - a self-contained beginning, middle, and end. My opening chapter was mostly setup introducing the characters, setting, and the situation. The plot was only in the opening stage and obviously there was no resolution - it was not a self-contained story. Anyone can start a promising novel, but it demonstrates real craft to finish a complete story. So next year that's what my strategy will be.