I have mistakenly sent my LTC to (M) address instead of (3) address I have mistakenly sent my litecoins to (M) as the starting letter of the address, whereas the Litecoin address now has changed to (3) as the starting letter. So can anyone help me to recover this?
Litecoin was having issues with users confusing Bitcoin and Litecoin addresses. To that end, they introduced a new address format for Pay-to-Script-Hash (P2SH) addresses. This new address format encodes the address with an M prefix rather than the original 3 prefix which is also used by Bitcoin's P2SH address format.

As any underlying address can be expressed in either address format, each address with an M prefix has an equivalent address with a 3 prefix. They simply are two different encodings of the same P2SH address.

Check out the address in question on the CryptoId block explorer for example:



When you search the address in question on this block explorer, you should be able to see both the M address that you meant to send to as well as the 3 address that your address now changed to, just like for the random example in the image.
 A transaction output will arrive in the same wallet with either of these two addresses given as destination.