You know when you downsize to a new house that is a little sketchy because of your finances, and you have too much furniture, or if they look too big for the new place? Everything is cramped, there is not enough closet space for all your clothes, and your cat (or dog) cannot stand how little room they have to play? You keep running into each other in the halls because the place is overflowing with your stuff, and complain about the tiny size of the backyard. The neighbors are weird. When it rains it leaks, and the dishwasher breaks often.
Moving into a smaller house is like getting diagnosed with [fill in the blank with your illness here]. For me it's my bipolar diagnosis.
Think of all the stuff (furniture, clothes, knickknacks etc.) in the house as all your hopes, dreams, identity and whatever else that made you you in the past. The house is your body- the body lets you do everything- achieve goals, chase after dreams, and fulfill responsibilities. But when you change houses against your wishes, you are stuck with all the stuff. The stuff that doesn't fit. The stuff doesn't fit with what you are capable of.
You can choose to not accept that you are living in a smaller house and keep all your furniture and your clothes. You're still going to have to face the ugly mountains of stuff every morning, and run into each other in the halls because of too much stuff. Life will be miserable.
Another option is to accept that you are living in a smaller space, and get rid of some non-essentials. You have to donate some old books, throw out old clothes, and maybe get rid of that extra chair that gets in the way that you never really bonded with. Bring cookies to your weird neighbors, after all, we're all a little strange anyway. This life is slightly more tolerable.
You didn't have a lot of choice because of financial constraints, and if you could, you would chose not to live in the house, but here you are. When you accept, you can be happ(ier) in the new house.
Bipolar disorder is a chronic illness- I live in this small house now and probably will for the rest of my life (unless there are miraculous medical advances, which would be nice). So I've thrown out some things I don't need so that I can live in my new house without getting frustrated: some grandiose dreams, goals, responsibilities that I had when I was healthier. The things that made me who I was- and there is no denying it, those things, like my career, how much I worked, and where I wanted to get to, defined me. I could have achieved all that with my healthy body/mental state. But this is the body that I have now and I choose to be happy rather than keep all my stuff from before.