Help with managing Credit Card debts

If all 3 of your cards are currently 0%, I can't see where you have scope to reduce your monthly payment if they are all the same 'minimum payment' amount each month.

If you're in serious debt, then perhaps start by having a look at https://www.moneysavingexpert.com/debt-help/

Your problem is not the fact that the debt is spread over 3 cards but the high minimum payments that these cards are taking.
Some cards offer a 1% minimum payment on 0% balances while others such as yours have a higher minimum payment.
Assuming that you can actually obtain a new card or cards, you could transfer to a card or cards with a 1% minimum payment.
However, consider the following.
1. You will almost certainly have to pay a new balance transfer fee to transfer the balance.
2. What are you gong to do when the 0% promotion ends? The higher the payment being made the quicker the balance will reduce and the less will be left when the 0% period expires. If you are having difficulty making your payments at the current level, what will you do when interest kicks in? If you have good existing customer offers on unused cards or are able to obtain new cards, you may of course be able to transfer the balances again but this is far from guaranteed.