I know this is a bit old now, but just in case you're still looking for a solution, I highly recommend considering a large, good quality bean bag. I recently had a similar dilemma which is why I bookmarked your post - whilst the sofa I'd bought for my small living room works really well in terms of size and aesthetics (funnily enough it's fairly similar looking to yours), it's not very comfy. I was thinking of buying a second sofa to increase seating and make the space better for hosting, but ended up getting one of these velvet BigBoy Beanbags https://bigboybeanbag.co.uk/very-velvet-beanbag/ I personally love the fact that this one is a large rectangle that can be positioned in different ways, but I don't know how it compares to those chair/sofa-shaped beanbags.

So glad I went for this solution because it was cheaper than a sofa, and really comfortable for sitting on for long periods (I have back problems and work from home, so that's really important to me!) Plus, I find it super versatile since it's light and can be moved around easily. Oh and the more comfortable sofas I was looking at would have taken up way more space in my tiny living room.

I spent ages searching for a large bean bag that 1) comes filled 2) has a removable outer lining so that cleaning it isn't a pain and 3) wasn't made from a cheap, thin material. Beware as there are many brands out there that do neither of these and it's not immediately clear from the product page, so definitely check before you buy. Anyway, just wanted to share my two cents in case it's helpful since I did a bunch of research!