I haven't seen that "x" beside an autocorrect word for eons, I wonder if SravanKrA is using an iOS version from years ago?
I constantly have this problem. What happens is as your screen shots show. In more detail, the word remains as you typed it until you hit Space, Return or the green or blue [Up Arrow] in the right hand side of the text message composition box.
A partial workaround is to watch for autocorrect ruining your flow and productivity by hitting space after every word, esp. the last word. If the word just typed has been autocorrected (i.e. when you hit space), press backspace and you should (but may not - hey this is iOS) see a text speech bubble appear above the word giving you one or more auto correct options - including the word you intended to type as the first option.
The other option is to turn autocorrect off in Messages settings. But of course you know that and just want to have the benefit of auto correct, be offered a choice to revert every auto correcting word in the message and without seeing the last word you typed changed immediately upon hitting "Send".