Hi it could end up being quite expensive as fleas reproduce so quickly.
You need to get a good vet recommended flea treatment for your bully
You also need your house completely fumigated (especially the room his crate is in) as eggs and fleas get everywhere. Over counter stuff doesnt work you need to call in pest control to have this done properly. All over the house will need to be done even though your dog doesnt go everywhere because fleas will cling to human clothes etc to move around.
Also for the garden you will need to pest control everywhere out there too but im not sure if your pest control will have the products or mot you may have to google good products for the garden. Maybe ul find some on ebay or something?
Then you need to buy flea shampoo to help keep them off your dog and flea repellent to use around the house/garden to try to prevent it happening again. A long and costy process but its worth it so that your baby doesnt eat any fleas/eggs and then develop worms etc. Also if he keeps biting and scratchin can get soars and infections and become irritated and depressed.
Hopefully somebody will be along soon near to your area that can help/recommend specific products as im from UK and they dont sell the same things . Good luck x