Is there a way to augment 450 mg. of Wellbutrin or may I increase dose to 600 mg. if I am taking Kilonopin?

I am diagnosed with generalized anxiety disorder and I have taken different forms of Wellbutrin for fifteen years now. I am now on the max dose at 450 mg. and I find it no longer works as well. In truth, I suffer from both depression and anxiety and I do not know which one causes the other. My question is -- can I safely take 600 mg. of Wellburin along with Kolonopin to perhaps counter the seizure effects? Or is the any other anti-depressant I can take to augment the Wellbutrin to give it a boost so it may become effective again. I warn you, I have tried many, many anti-depressants all to no avail and it is so inconventient as I must put my life on hold for several weeks to see if it works and I always have a downward spirtal when I get off Wellbutrin. Please offer an advice you may have. I greatly appreciate it.