A bit of personal experience here. I have always found that relaxed static stretches are enhanced by doing them right before bed. Yoga uses corpse pose at the end of sessions because there is supposed to be a link to mental and physical relaxation. Also I don't believe you've been keeping to the stretching routine for 3 years. Only a month ago I realized I wanted some more flexibility again and all I've been doing is static stretches before bed. No dynamic stretching in the morning this time as I don't have the time but I estimate only another 2-3 months before I can get back to full side splits based on current progression. Start a training log on here. Log every day exactly what you do, every day for a month and measure the width of your splits using a measuring tape at the end of each week. If you do that we can easily pick out what you're not doing or where you might need help.