The thing about marriage is that two people are accepting each other as a semi-permanent factor of their lives. Every fault, every strong-suit, every difference, every similarity is something this person should have accepted or should have been willing to accept before he proposed. These are all things you'll have to deal with until you file for a divorce (or, more optimistically, until death does you part.) He should have known about your passion for horses and your desire to get one. Contrarily, from your first post (My marriage has been extremely rocky ever since the mention of getting back into the equine industry came about 8 months or so ago. With the mention of that, I went forth into the equine world again and bought a horse.) It sounds like the decision was made by you and you alone, however that may NOT be the case. I don't know the whole story.
Sit down and talk with him first before you assume that he's as bad as he's made out to be in this thread. Communication fixes everything. Gauge what to do from that conversation. Maybe he's afraid of horses? Take him out to the barn, show him a good time. Maybe he's afraid you'll get hurt? Support him and make him feel secure that you /won't/ get hurt. Maybe he feels like you left him out of the financial decision and therefore thinks all those things he does? Apologize profusely and ensure to him that you'll include him in major financial decisions in the future. You're a couple now, a team. You should have included him in the horse hunt and money making decisions. (Again, just operating on what /could/ be the problem.) Find a happy medium. Go to his hockey things with him and provide incentive to take an interest in your hobby. Open the door, lead by example and provide room for success in this relationship by doing so. Don't just up and call it quits over this one rocky period, because your marriage will not last if you operate that way. Remember, the bond of marriage is supposed to last for the rest of your life. There's a TON of room for other rocky patches. Don't rule out couples counseling either.
Now if you've tried sitting down and talking to him, finding ways to compromise, tried the counseling, and see no change? That's when you have to re-evaluate his character and whether or not you want to be tethered to him for forever. Some men do manipulate their women to the point of no return, I would know. I've witnessed it several times in my family. Those types will gripe about horses until she quits, then she picks up a book club. He'll gripe about that until she quits, then she'll pick up a college class. He'll gripe about that until she quits. Eventually he has manipulated her into being a stay at home mother with no friends and no ambitions. It's THOSE guys you gotta ditch before those wedding bells even get a chance to ring. It's you who has to know when to quit feeding into him.
And I do want to say that it's true - a marriage is to enhance your life and your separate lives don't disappear when you're dating or married. But you have to remember that a lot of people with insecurities demand more attention than others, what may be enough time spent together for you may not be enough time spent together for him. You have to find a happy medium that doesn't enable him to make your separate life disappear.