Hi again, It sounds like you've done your best to find a cheap place (even though it seems high to those of us who don't live in a major city.) And, I don't blame you for not wanting roommates at your age--I honestly don't think it'd be worth the extra money to compromise in that area or on safety. It's very admirable that you're contributing money to your mom, I'm not sure what to tell you there except that I hope she can find employment soon.
I think you know what to do: cut down on travel and food, and put the extra money saved towards your loan and investments. Once you become financially independent, you'll have ton of time to travel :) Even though it's expensive, you're fortunate to live in an area with high culture, so utilize all of the free things that Chicago has to offer instead of traveling elsewhere.
As for what to do with your savings, it's simple math. If your loan is 4.25% but you're making 7% on your IRA, pay the minimum on your loan and put more in your IRA. If you aren't, or if you're very risk adverse,(honestly you should choose a different fund because 7-8% is an average return) then put all of your savings towards your student loans.
You're doing a really good job! Don't be too hard on yourself, I think there are simple ways to cut back and still enjoy life--or maybe enjoy it even more :)