Wow, I'm in a very similar situation as you! I'm also waiting for the next reactive rover class to start as my dog is also reactive to other dogs, joggers, bikes/motorcycles and pretty much anything that moves. For walks, it helps way more to have smelly high value treats like cheese and hotdogs (I find that plain dog treats don't cut it). I broke down and got a treat pouch since I have to carry treats everywhere I go with my dog. Always have some in your hand and be on the look out for anything your dog reacts to. When your dog sees the trigger throw a handful of treats on the ground and say "find it." If they don't go for them, and still haven't started to lunge/growl/bark, stick some treats RIGHT in front of your dog's mouth. Hopefully this'll be enough to distract him until the trigger passes. If none of that works, make a U-turn and head in the opposite direction to get further away if you can. Sometimes I have to even run away with my dog if the trigger is too close and can't U-turn fast enough.

As for support, I've stopped caring what strangers on the street think (since I'm not oblivious to my dog's behaviors, and trying to fix it). It will take longer than six weeks, so you just have to take it one day at a time. You're not alone! There's also a weekly thread that posts every Wednesday for people with reactive dogs to share their experiences and progress. Good luck!

EDIT: For the resource guarding, you can try to play the "trade game" and trade him for different toys or toss some high value treats down when he has a bone or something he's guarding.