Fiance objects to my hermitage

When my grandmother passed away almost 5 years ago, she left me her nice little mobile home. It's located in a beautiful, quiet, senior mobile home park where I own the property it sits on. It costs very little/year to maintain it. Though I am not a senior, my neighbors look the other way as they liked my nana and I both.

I decided after receiving it, to make it my hermitage of sorts. I redecorated it with a number of crucifixes, statues and icons. I discontinued the telephone service. I had the electricity and gas turned off. When I spend time there, I use candles and oil lamps, take cold showers and sleep in a heavy sleeping bag. It really is a gift to be able to get totally away from things less than 5 miles from my own house.

It's near my work, so I drop by at least a couple of times a week with my lunch. I also try to do a "weekend" retreat at least every other month, from Friday evening to Monday morning.

When I told my fiance about it -- a little more than a year after we began dating, she demanded a key to it and I declined. I want to keep the space as my own private get away. I said she would be welcomed to use it for her own planned retreat, but otherwise it's my private space.

She's not at all happy with my decision. I have to ask, am I being reasonable? In a way I think the hermitage has helped keep me sane and strong during tough times. I really cringe at even the thought of someone trying to redecorate it, someone wanting to turn the utilities back on, someone dropping by while I'm reading or immersed in prayer. Your thoughts are most welcomed. Thank you.