How can I convince myself to break up?

I have been in a relationship for the past three years. It hasnt been easy at all, as he had money big problems. we are living together for 2 years now. 3 months ago we just moved to our dream property, with our horses, chicken, dogs and birds. It's unbelievably beautiful here, but I notice a change in me. I feel annoyed of him all the time, it annoys me that he takes so long to get things done for me (fixing things or simply unpack three boxes f books that are waiting there since 3 months). I am the big earner between us, I pay for pretty much all the lerks and perks. He just became a job with our landlord, which will pay a bit of the rent plus give him an income. It seems like, that I have to push him to do things, I wake up at 9 because I don't have clients any earlier, he will not put on his alarm, get up and start working before me. He actually end up leaving the house later than I do (as he takes forever with his morning ritual - breakfast, tea,...)....
He is 18 year older than me, I am just 24 and feel so much how different we had become. I am not a romantic person, he is. I like it fast, he likes everything slow. I am very spontanious, he needs 2 days before information. I think he is a great guy, for someone but not for me. He starts talking about kids and wedding all the time, a year ago, I did too but not in the past 6 months. I don't even say I love you anymore, and avoid body contact. I actually imagine myself with other men already, as bad as it sounds.

The reason I find it so difficult to break up is that
1. We have so much stuff together (the house, all the animals, all the furniture)
2. He is 42, his time is running out to become a father in his opinion
3. He had got his heart broken very bad 5 years ago (she broke up with him after 10 years and didnt let him have contact to stepkids)
4. The friends I made here are all his family and friends (i came from overseas and simply had no one here)
5. I would be scared living alone with all these scary animals in australia
6. He is so supportive with everything like a best friend
7. I manage all his accounts, bookkeeping, paying of debts, without me he wouldnt be able to handle all this stuff (he let it go for 5 years before I met him, he receives mail and just puts it somewhere in the draws).

I really don't know what to do. Is there anyone that had the same problem? Please don't judge me, I think i would try to shake my friend awake if she was telling me my own story. It's very very difficult. It's not only the hurting for him, it's the splitting of everything and my parents love him.

you obviously still care for him or you wouldnt worry bout him,but its as you would care for your dad.you are loseing respect for him,forget the possesions,the most important thing is happyness and peace of mind.tell him its spent,help find him alternative accomodation,unless of course you dont feel secure without him other men?try it,you will prob find you susspect they after your goods and chattels.good luck.