Forgot to mention that I undervalued myself early in the interview process and gave a salary range of 60-80K.

They gave you the high end of your asking range. If I were hiring, I'd think about pulling the offer. Kill it, wait 6 month, re-visit. You're going to be in a much better position since 1) you won't be on a 6 month job hunt, 2) you'll be employed, and 3) you'll be able to better justify your worth.

More practically, if you go this route, you're potentially risking a continuation of the job search. We can talk about value as much as we want, but the reality it sounds like is that this is your 1st and only offer in 6 months. Are you really willing to keep on searching?

For additional background I have a BA in Psychology, an MA in Educational Psychology, and was 2/3 of the way to a Ph.D.

Irrelevant to me. They just look like extra cost. If you want to go up to 90-100k, that's bachelor with experience or master's DS level range for me. You'd be overpaid for your qualifications if I were looking at hiring.