To dislike WFH….

Plus one for a proper desk set up. If possible in a separate room. That way you don't feel like you never leave work. I would also recommend a quick walk around the block before and after work. It doesn't need to be long, but will give you a sense of separation between work and home even though you are in the same place.

I would also recommend seeing up a few 'coffee calls' with colleagues with the express purpose of catching up / chatting. Only for 5 or 10 minutes, and you can do it individually or even as a group. You won't be the only one feeling this way. I encouraged my team(s) to do all of these things and it made s big difference.

Does your employer have a office-based or hybrid option?

If they do - ask them to switch you to it.

Well, if you only go in once a week you are not going to know them are you? It's very different to going in every day.

I agree with this. I am retired now, but in my working life would have hated to WFH. Fortunately that was never going to happen, given that I was a receptionist. The best part of going to work, for me, was always the other people working there. I also look upon my home as my sanctuary, and would never have wanted work to encroach upon that.

I agree with @MeganM3
Both in that working in the office, when other people aren't, is very different from pre-2020 when everyone was in the office, by default.
But also in that I reckon, once you start adding in commute which can extend your day considerably, back on to every working day, and then all the annoying things about other people (different temperatures, inane chat, some want the radio on, others don't, etc, etc) sharing your space, you'd soon be longing for home again.

YANBU to dislike it, but you would immediately improve your day by not sitting on the sofa all day. You should be sitting up at a table. Your posture and your digestive system must be taking a hammering.

Also, go out somewhere every day - both a walk during your lunchbreak for fresh air and a bit of exercise, but also make sure you do things each week to get a fix of being social. That doesn't have to come from work colleagues.

Agree with this. There is no longer the same buzz going into the office. Some days it is like a ghost town.

I also agree with the poster that said you should be sitting at a desk and not the sofa. Do you do teams/virtual calls from the sofa? Not sure how this can work.

Rose tinted glasses. Also, it's not the same as before, there's less of a social element in the office these days. I barely know the people in mine, I go in once a week.

People can be unbearable, however I think there is a general human need to be around other people.

First thing: Why are you sitting on your sofa and not at a dedicated work station? Your employer should provide a desk and ergonomic chair etc. Sort this out as a priority and book some Pilates classes to sort out your back.

Might it be possible for you to work from a library or a desk hub if you are missing day-to-day human interaction/company?

Don't forget how unbearable other people are

I would search for other roles or see if your present role has the potential to be hybrid. I don't think WFH 100% of the time is healthy for the reasons that you've given. I WFH however have other things mixed in, I work in a university campus on Mondays and attend a running club, go different places other days of the week etc. it's absolutely normal to need more mental stimulus, change of scene and social interaction I think.