OP I think you are doing the right thing to get checked by your gp. You sound low.
I lived alone for several years & I took great comfort in making my home (a small 1 bed flat then) as cozy as I could. I also had a low income at this time so did this with small things. I surrounded myself with books, house plants, candles, throws, postcards of artworks & over the years I had collected some original artworks (mostly original prints - etchings, screen prints etc) which I hung in my living space.
I spent time finding the perfect cups & plates - ones that brought me joy everytime I used them.
I worked & studied during the week so weekdays were busy but I used to make a little ritual of making myself a lovely weekend morning breakfast most weeks.
I had a cafetiere so I made lovely coffee & used my gorgeous cup & saucer. Organic free range boiled eggs, in matching eggcup, good bread toasted with real butter & a great book to read.
My flat was on on the 3rd floor & was generally bright & sunny in that living room. I'd put Frank sinatra on the stereo & just sit & luxuriate. It's several years ago & my circumstances have changed since then but I can still close my eyes & bring myself back to that room & that feeling that all was well in the world. I had created a safe haven there.
I think we all need to do this no matter whether we live alone or in a busy household - it's easy to get caught up in the daily grind & just exist day to day. But it's very bolstering to create little pockets of restorative self care / relaxation.
I now do it by buying supermarket flowers (& very occasionally nice florist ones) in a couple of rooms. Trying to keep on top of housework midweek so when we come in after work the house is not in chaos. Nice scented candles & proper good food.
Real coffee in the mornings. Still surrounded by books!
I don't always succeed but they're the intentions!
I wish you well Op & hope you refind your peace & joy