Open Question: Can I send all of my Creditors a settlement letter offer?

I have about 7 credit cards that I have had for several years, which have all been closed. They were closed by a debt management program, but I got dropped from that program because i lost my job. After I found a new job, i started back making minimum payments directly to those creditors. I am literally sick and tired of paying these cards and feel like I am not making any progress because of the sky high interest rates.
My question is….Can I send each creditor the below letter with an offer to pay off these cards for 50% of each balance and see if they accept???

To Whom It May Concern,

According to your records, I owe an outstanding balance of $_ 1000- _, in reference to account number _____________.

I feel I have a moral obligation to pay this debt I owe; however, I do not have enough money to pay you in full. I would like to offer you a settlement amount of $_500-_ to consider this account paid.

Please accept this offer, as it is all I can afford. If you accept this offer; please send me a letter that you are in agreement to the following terms:

1. You accept a one time lump sum payment of $_500-__ to satisfy my debt of $__1000-__ owed to you.

2. You agree to cease collection attempts.

3. You agree to report to the credit bureaus Experian, Trans Union, and Equifax that this debt has been satisfied. Preferably that the debt has been paid in full; however that decision rests on your shoulders.

4. You will send proof of satisfaction to me stating that the debt has been satisfied as soon as my funds have cleared.

When I receive your letter I will immediately send you the agreed amount so I can get this burden behind me. I appreciate your consideration of my offer and thank you for your time.

…………….
Just to add, which might not make a difference….since I’ve had all of those cards, I have had late payments on pretty much all of them, but am now trying to get back on track.