Hi there!
I definitely don't have all the answers, just wanted to give you some 3am support! I think you need to figure out your gameplan and budget to focus on the current debt, and also focus more (but not entirely) on debt vs. credit repair as that will follow naturally. I would call that finance company though and see if they will remove that late. If they say no, write a GW letter. If they still say no, think about a PFD to settle for less once that bill is paid down a little more.
Some things that worked for me:
Keep any open account current at the minimum.
I have a notebook that I prepare in advance monthly logs of what is due to whom and when, in order of due date. It's always out and near my computer as I find paying online easiest. I pay at least the minimum on CC with a balance as soon as the bill generates to avoid lates, and then at the cycle end date I pay the entire balance to keep my utilization optimal for the new charges that will come thru the next day when it also reports.
I called every one of my CC companies and nicely threatened to go elsewhere because their interest rates were not as good as other offers I was getting. They lowered them to keep my business It does not always work, but it's worth it to try.
Find ways to cut corners... cook at home more, try generics to see what ones are acceptable, make sure you have the best plan for cell, cable, internet and phone etc.
As far as the delinquent accounts, if you could list them and when any are scheduled to drop off that will be very helpful in figuring how to work that half into the whole picture. Remember not to settle anything negative without a PFD response from them that is acceptable.
And on a final note tonight, don't overwhelm yourself, take it slow and steady. 