Can you bring the outdoors in with plants? try colorful art.

Can you tell what seems the worst offender with that feeling you mentioned? such as, the paint color??

I think the ceilings bother me the most and they are popcorn which I really don't like. Also the rooms have no nice features - don't know how I ended up buying something like this which is the opposite to what I like.

You're addressing it now, and maybe one change to each room - even patio needs a chair so you'll enjoy every inch of your property!! to look at the beautiful sky.... ok I'll stop... :)

Can you post a photo of your rooms, especially the opening? I bet with a designer, or if not, houzz or a friend could suggest your 'kind of thing' for it. I'll wait, but one more in case this might suit:

Dominique & Anne-Marie · More Info

I had one long wall [the one shared with neighbor] which you could do treatment/design on, with paint or wallpaper, even neutral, even sheen.

But what is your groove look? [is that a right word?]

Medfield Formal Living Room Design · More Info

Narrow dark town house

I would add large mirrors to the walls to open the space. It did wonders in my friend's tiny kitchen and made everything feel less small.