Only constructive responses needed

my friend and her husband were going through some stuff shortly after they got married. I would advice both of them time and again.
So after a while her husband started to depend on me for what to do to impress his wife and I had no problem with it.

Years later he tells me he wanted to go into business with me only that he knew I didn't know a thing a bout his kind of work, I later on realized he was trying to keep me close so I declined the offer.

He kept coming up with excused to see me including showing up at my place of work and he is a good person who I have grown to love as a friend. Problem is I think we are in an emotional relationship now where we all go to each other for our troubles. He asks for my opinion on his everyday matters including big decisions I shouldn't have to make.

I can't cut him off I genuinely care for him, I cannot tell his wife she won't understand but I can't keep up with this emotional relationship that he wants. How do I let him off easily and still keep both of them as friends.

He is in love with me, he talks of me thinking about a future with him but I already have my own stuff to deal with. And before you think it, DONT we have not had sex. I don't plan on doing so.

Advise me