how can i fix my credit?

Keep one for emergencies only, cut up the rest and pay them off. Hopefully you have a job. And deal only in cash until you feel you have the discipline for credit. When you like to spend money, it's difficult to have credit cards. Never carry them with you. Impulse buying can really do you in.

If your late payment was reported to credit agencies, yes, it will negatively impact your scores. And being over your limit itself may do so as well.

But over time your scores can recover if you show responsible credit history.

The key things:

1) No negative reports of late payments of failure to pay.
2) Balances well below the limits. If you are even close to your overall credit card limit it will negatively impact your score.
3) Time. You need to show a history of this credit behavior for even higher scores.

Basically what they are looking for is to see if you are overextending yourself, the number of credit cards you have may itself be a negative though canceling them can make your balance to limit ratio look worse.

The bottom line is to stop spending on the cards and start paying them off. This makes sense for reasons other than your credit score. You already got hit with a late fee, just be more thrifty and get ahead of the spend. It will pay off for you in many ways, the least of which is your credit score.

I had the same problem, except it was one credit card with over 3,000 racked up on it from a trip to Europe... those currency exchange fees really get you.
Anyway, like the other people are saying, cut up your credit card, and the next time you get paid, set aside the part of your paycheck that you need to live (rent, food for groceries, gas money) and that's IT. No spending frivolously till you have the cards paid off. Then, take the rest of your money and put it on your card IMMEDIATELY. If you don't, you'll end up spending it, trust me.

I did that and I have an excellent credit score now, so don't worry. As long as you're not making just the minimum payments or late payments, it'll be okay.

(I was told this by an accountant) Get rid of all but two cards, use one for emergencies only (pay it in full at the end of the month) and do not use the other one at all but pay the monthly interest or APR on it. The credit records will show that your making your payments and your credit will be fine in no time.

the best thing you do is to cut your other credit so that you can pay the over charges of your one credit card that you have problems

It will affect your credit rating for quite some time.
Also, as advised by @eoe - Keep one for emergencies only, cut up the rest and pay them off.

If your creditors report about your late paid credit then it will make an effect on your credit card. I will suggest you to first concentrate on one credit card.