Thanks man.You are a bit similar to me. I unleashed my interest in history by making a compromise....I made it one of my main hobbies.
History based career is very tough one to orient after you have commited to something else in your studies.
You can still study history while you work your engineering career. What you signed up for only becomes a real problem if all your passion is sapped for it. It need not be total lost cause simply because you have a bigger passion now (that you can dedicate your quality free time to)....given you still got solid passion for engineering too right?
Yes I love Engineering thats why I preferred it over economics or medical.
My interest in history developed when I first study about Mughals and battle of panipat in 7TH grade.
Since then I've read tons of books, articles on internets, watched documentries but my thirst for more never ends.