That is indeed a LOT of honey malt. However, it is going into a dark beer, so it may add a really unique and neat flavor. Could be really good!
Do what I do when a "woops" brew comes along; brew it out, bottle/keg, and taste it before anyone else has a chance. If it has an apparently different flavor then come up with a modified style name. "Honey Porter" or similar. Or, have an explanation for it like "some folks find Porters hard to drink on their own, so I customized it to have a bit of sweetness and added smoothness to round out the harsher dark grains."
Or just have a good story about it at your own expense. Either way, a good beer with a mistaken grain bill is still a good beer. Let us now how it turns out!