I’m not an expert but ….
From what I’ve been told, by physios, if you have lower back pain it’s likely the muscles above and below that are tight. Ham strings, quads, hip flexors, middle and upper back. Look for exercises/stretches that work on those areas, be careful following some of the online videos that may work or stress the back and put more tension in that area. I’d say it’s important to relax (the meditation bit) a bit at the end, it helps to relax the muscles before you start moving as you have just stressed them, just a few minutes helps.
I’m suffering a lot at the moment with all of the above but I’m 53 so maybe I should consider myself lucky as some have said they’re suffering in their 30s and 40s! I was in tears this morning with it, just really fed up with it rather than the pain. Riding has become difficult as I seem to be in a catch 22 thing at the moment, if I ride my muscles get tight the next day which leads to back pain which means I can’t ride, that’s even with a lot of stretching. I tend to go for it when I ride and it’s hard to keep it slow as my head is riding like a 30 year old but my body is reacting like a 70 year old.