[This was generously contributed by someone who has experienced burnout, to help others]
I self-diagnosed with burnout and can't be sure that other issues such as grief/trauma and the particular situation with my employer etc weren't more relevant.
In short, after a particularly pressurised 12 months at work, I began to feel constantly exhausted, stressed and hopeless, became progressively less effective at my job, felt like I had "brain fog", lost confidence in my abilities (work and personal life) etc, etc. I'm sure you've seen it. I had a pretty brutal employer (new owners running down the division as not core to their business strategy, 50% of my team made redundant after I'd left and during Covid - nice!) and nothing improved for me until I resigned from the job.
At the time I did mention once to my line manager that I thought I had burnout but it wasn't sympathetically received... perhaps it was viewed as an excuse? At the time, I didn't realise how much it was affecting everything (work and private life) so I just kept going/holding everything together. I did reduce hours to 4 days a week but the workload remained broadly the same and realistically it was often working from home rather than getting a proper day off.
Resignation would be my advice to anyone in my situation... ie non-work commitments such as child care/elder care etc that weren't optional (or a lifestyle choice... grr) and an unsympathetic employer demanding ever more. However, I wasn't financially able to do that for many years and some of your clients (eg older women who are less attractive to employers, suffer the "motherhood penalty" on salary and negative attitudes to flexible working) may find themselves a bit trapped. Some strategies for managing the unpleasant situation that I couldn't realistically escape from would have been very useful.
All is good now. Partly due to the timing with Covid, I've decided that I have accidentally retired and although I will have a less luxurious retirement than I might have had, I'm just so happy to be out of the situation and looking forward to the future. Once family commitments permit, I may even start a small countryside business.