Hmm, well, to be honest, Finance seems a bit boring, and finance doesn't have much to do with investment banking. If you want to go into investment banking, think carefully. Sure you'll make a lot of money, but you also need time to spend the money! Also like you said its stressful. It's not as glamorous as most people think either. However, there are loads of things you can do in investment banking, not just trading; there's risk assessment and stuff like that which you may find interesting.
Engineering, though lower paid, would be I think more satisfying, but that's just me. Would also give you time to do some of your other interests!