[vishenda]

Yes, this is negatively affecting your credit score. It shows lenders you don't effectively live within your means, and you're over-exerting your spending. You can try to increase your limit, but creditors may not even attempt to do this if you're already over your limit. The best thing to do would be to pay this credit card down immediately. Don't increase your credit limit. Make your usual payments to your creditors as long as you are not behind.
In terms of your credit score they judge it by a debt to income ratio.
so if your dept is 10,000 and your income is (an imaginary number) 30,000 your ratio is 10000/30000 = 33% (this is an annual example)
I think a creditor will look at your monthly ratio. The higher the percentage the poorer your credit is. As well, late payments and such don't help out. If you have a good excuse and have caught up with a behind credit bill you can call them and ask them to remove the record of the late payment. Some will, some wont.