Hi @Dothemo, I think that meaningful change is definitely possible at any age. I find that the issue, however, is overcoming the expectations and prejudices of society. Based on Schema Therapy, I would say that this issue is actually society's problem, not mine. This perspective works really well for me, though I do have to keep working at it.
I lived with undiagnosed bipolar disorder until, in my late thirties, I was hospitalised and subsequently diagnosed. This diagnosis, and especially the treatment, was positively life-changing for me (though it was a slow and gradual process). The problem, however, was that this hospitalisation resulted in the loss of my employment. My qualifications are in a very specific field, and suitable employment can be difficult to find. In fact, for the job that I lost, it was a period of 1.5 years from application to commencement, and I was only in the job for a few months. After losing this job and being diagnosed with bipolar, I thought that I would never be able to work again. This was due to the necessities of living more 'gently' so as to promote mood stability, but also in part to thinking that I was too old (and maybe to unwell) to start a new career. My previous career would have been far too stressful for my wellbeing.
Meaningful work has always been one of my key values, so I was extremely unhappy with the prospect of never working again. Luckily, after a lot of psychological therapy I was introduced to Schema Therapy (which I noticed you have also used). This seriously changed my life. For example, I gained a new perspective on being too old and unwell to start again, and realised that these are society's issues and not mine. It took 3 years, but I eventually was able to find a new career path that fits with my values and is much less stressful than my previous career.
So, my advice would be to live according to your values, and try not to take on the values, prejudices and expectations of others. Live your life your way, and meaningful change is always possible.
All the best, AF