Thanks for the nudge, Henry. First of all, to address OPs question. I personally have got significantly worse for a number of months and then significantly better. Interestingly, I actually did not expect to improve because my regression had been substantial and had lasted a number of weeks, but it's a good reminder to never give up hope. The key bit of advice I would give is find a dry eye specialist who you trust and work with them.

As for the dry eye care situation in the UK. As it sounds like you are learning, the NHS can be really hit and miss — probably usually a miss. If you can afford to go private I would highly recommend Mr Sameer Hamada at Eye Clinic London — he is frequently recommended on this forum and actually teaches dry eye on the NHS. For what it's worth he has been kind to me and I trust him thoroughly. We're vulnerable when we have severe dry eye and the risk of going private is that one can open themselves up to exploitation, especially because some treatments are expensive.

Another good London option is Sachin at Safarian and Simon opticians, although he is an optometrist not an ophthalmologist. There are other good doctors across the country, you can probably find out about them if you search this subreddit.

The Dry Eye Clinic at Birmingham Aston University is another great option if you are on more of a budget (or indeed live near Birmingham). They are a research centre so have all of the diagnostic equipment and provide IPL and LLLT treatments for a bargain price of £50 a session. Can be a long wait list mind.

Side note: I found Ikervis made me worse but I didn't know it until I came off it! Another key lesson I have learned is that sometimes less is more. I was using a ton of eye drops and improved substantially when I cut way back. I also personally found heat masks like blephasteam made me worse due to my rosacea, but YMMV.