OP, I agree with PPs that you don’t need to worry about fats, as long as you are eating healthy fats and not to excess.
I eat low carb all the time (on medical advice), and I did lose weight when I started the diet, without trying and without feeling hungry. I don’t restrict fats. Fat fills you up and stops you feeling hungry. I wonder if not enough fat is one reason that you feel that your diet is not satisfying. Nuts are fine on a low carb diet, in small amounts, and very healthy.
I also agree with PPs that Tim Spector is great. I think his videos and podcasts are very helpful.
Personally I wouldn’t eat Quorn or protein shakes, because they are ultra processed foods which are likely to damage your microbiome.
Have you tried yogurt or kefir made with soya milk? These contain protein from the live bacteria in them as well as from the soya.
I can recommend 100% cocoa chocolate if you haven’t tried it. It’s quite satisfying and really good for the microbiome (it contains polyphenols that beneficial microorganisms feed on).
Have you thought about intermittent fasting? I haven’t tried this but some people seem to have good results with it. There is information about it on Tim Spector’s Zoe YouTube channel.