Hi there and thanks for posting on PetCoach!
I'm sorry to hear Tom is having all of these health issues. Poor guy!
Spinal injuries can take a while to heal and some do require surgery. Spinal injuries are also often quite painful so making sure Tom has some pain medication on board would be helpful. If no pain medication was given, you may ask your veterinarian about this.
Special food can be prescribed by your veterinarian or an appetite stimulant medication can be prescribed by your veterinarian to help increase his appetite. You can also heat up the wet food at home a bit to bring out the flavor and may entice him to eat a little bit.
Ticks and fleas in small young kittens can actually cause anemia (low red blood cell count) which can cause weakness and lethargy. The ticks will need to be safety removed either by you or your veterinarian. If you are unsure how to remove a tick, I have linked a video below. You may use a bath of dish soap (Dawn dish soap works well) to help get rid of flea infestation until he is old enough to be on a month flea preventative such as Revolution or Advantage.
If Tom is still not doing well, I would recommend he see his veterinarian again to see what else your veterinarian would recommend.
I hope this helps and best of luck to you!
https://youtu.be/0wotB38WrRY