New and tired of failing

Options
I'm 57 years. Was 103 lbs until 45 then ballooned to 200. I have limited space to exercise as we are building and am living in a 31x12 travel trailer until they finish our house. Our property on busy country road so biking is out and I'm not motivated to walk by myself. Any suggestions for keeping active. I am trying to cut meat and dairy out of my diet by currently limiting meats to dinner time . Hope to eventually reach vegan. I am trying to reach my goal of 125 without help from family who love me the "way I am".