Neither of these constructions exist, I'm afraid.
Both 'I use to do' and 'I'm use to do' are incorrect.
These are the correct constructions:
I used to do that = Lo facevo sempre (nel passato), ma non lo faccio più.
I am used to doing that = Sono abituata a farlo ( nel presente).
Here is a link with a good explanation:
"Used to" means you did a certain action for a period of time ,but now you DON'T it anymore.
" be used to" means you often done or experienced a certain action, it is not strange or difficult for you.
I hope it helps.