recover diet... PLEASE HELP

i'm coming off a year long injury that kept me from working out...(nerve damage).... at all... i lost about thirty pounds while adding about 1-2%bf....now at about 11-13%

i now can start working out but i have to start extremely slow... about 50% intensity....

should i slowly work myself into a bulk diet to feed my muscles while muscle memory kicks in... is this crucial? i've been eating only 3 meals a day for a year... should i really pack in the calories and not over obsess about it being clean to try to get somewhere back to where it was?

i'm guessin that for a few months everything will go to my muscles... seeing how i haven't used them at all for 12 months... and not be stored as fat.. correct me if i'm wrong.... never had to do this