My father just can't keep his mouth shut. He is so critical of me, my home and my belongings. "I don't know what possesed you to buy a stainless steel refrigerator" "You guys have too much stuff" "You can't cry for everyone" (My 49 year old stepbrother died of cancer on Halloween
Our house is 1,000 sq foot, there's not too much space to get away and he says something stupid to me every dang morning.
So if you really can't handle him living with you, help him find a senior living situation and move him. That is an OK choice. No guilt necessary.
IF you want to try some more to make this work (and it is totally up to you), you could try setting some boundaries and rules.
Here are some possible options:
Make your possessions of limits for discussion. You have what you have and you don't need or want his opinions about it.
Try for humour in your responses: "I was hoping for a pink refrigerator but that would be a custom paint job, so I settled for stainless."
Give reasonable, nondefensive answers: "No, we don't have too much stuff, we have too small a house. We love it all, though." "I'm not crying for everybody. I'm crying for someone I knew and cared about." Don't get drawn in to an argument.
Try creating some breaks from him. Can he get his own breakfast, while you go for a walk, or to the gym, or have coffee with a girlfriend on her way in to work?
Perhaps he could go to an adult day center one or two days awake, giving you respite. Or he could visit the senior center on days they have activities he likes. Or he could have his lunch there daily. He could join a senior bowling league. He could join a model railroad club, or a golf league, or a birdwatching group -- anything that he has an interest in and perhaps did in younger days. This will have two benefits -- get him out of your hair for a while, and also give him some new topics of conversation.
You may be able to find ways to make his presence in your house less stressful for you. But accept that it is also OK to find him a new place to live.