[:@] Sorry to see that, man. Luckily the fuse broke in a very common, and easy place to fix. Gonna prolly want to take some basswood or maybe even some 1/8"x1/4" ply strips and first CA the body together after you clean the broken area up. That can be done simply with the hobby knife. Clean the wound, set the fuse back together with the strips, then using the same thickness balsa sheeting, cover the area that you trimmed away. Make sure to peel back the monokote so you can fix everything without the mess. After it's all sheeted and rejoined, you could take some 5min epoxy whip it up and put a thin coat in the inside along the strips as well as the fault line. Then with another batch add a little denatured alcohol to the expoy and brush that to the outside. Let it cure and then sand the outer sheeting with your sanding block till it's smooth.
That should hold the fuse together very nicely.

Traditionally that spot right at the back of the wing mount on low wing or mid wing planes tends to be a nasty weak spot. Very common spot to break. NOt to hard to fix.

The firewall is also a simple fix. Cut any monokote from around the mounting area so you can work without it getting in the way. You prolly should use a new firewall piece, buy some plywood same thickness and trace the orginal's shape onto it. Cut and sand. Then you'll clean up the original epoxy holding the firewall with some sanding. You can epoxy the new firewall in with some straight 30min epoxy or if you want a super tight hold (with some extra weight) buy some fiberglass cloth from your local hobby shop. With a brush and some lightly denatured 30min epoxy, brush epoxy onto the firewall and the joiner, then lay some cloth onto it. Make sure there's enough cloth to be folded over on two sides of the nose. Then brush some more epoxy on top of the cloth to soak it up and help bond to the firewall better. Let that cure over night and then sand the area smooth. Especially on the sides of the nose where monokote once covered the area. Then simply fuel proof the firewall and recover the bare spots with monokote, remount the engine and tie the battery down for the next flight.