I'm really sorry you are going through this, it's so difficult to see our pets suffer.
Based on the general symptoms you describe, it could be so many things that it would be unwise to speculate.
The only thing to do if you can is call your vet for advice or bring him in again if this continues. I'd certainly have the vet examine the ears themselves (to rule other common stuff out) if/when i bring him in again.
Makes sense though (just common sense, not medical sense as i cannot offer that) that the head tilt has a high chance of being related to the seizure if it's never happened before and the two happened one after the other...and this particular seizure was extra long. The vet might well see this connection for your particular dog and be able to make better sense of it. This also might be a common temporary side effect. A phone call certainly couldn't hurt. Keeping fingers crossed for you