How long have you been doing this routine?I have a 15 minute stretch routine I do every morning- starts with extensions (MacKenzie style), to child's pose, then (on my back) knee to chest, hamstring, piriformis stretches, open book rotations, then downward dog, hip flexor (psoas) lunges, groin stretches and end with a valgus stretch I came up with on my own (to access tube stance position).
I've had low back issues since my twenties and even stopped surfing for years at a time because of it. Then I started the McKenzie Method about 8 years ago and it's no longer much of an issue. It took about a year of doing it before there was a significant result though.