No its defiantly fixable. The switch though I don't think can be simply glued back together, but you can try. It being a crappy aqueon is going to make it harder
. First though can you take it off the tank and flip it over. Remove bulb and the condensation "sheild" if it has one. Take a picture of the underside please. I have one of these for a 5 gallon and will tinker with mine to see if you can get to where you need to get too to fix it. Mine has already been majorly modified and I forget what was originally in it( apparently crap since I took most of it out).
Also if this is a fixture for a 5 gallon you can more then double its output using the materials already inside it and a little tinfoil. You would need some tools though. You don't change much of anything, you just get rid of everything that is not the socket and center the socket. What I do know/ still have is the main socket/ switch which is actually fused together. The switch is built into the incandescent socket, which is like riveted together
. Below is a pic of my fused socket. You can see where yours broke. That part that broke off yours is actually 3 pieces. The part you push in, the plastic nut, and part of the threaded area which is where it actually broke.... On my fixture that little plastic nut is really the only thing holding the entire socket and bulbs in the hood. But IDK if it was like that originally...