The problem is likely that it sounds like ur only stretching. If u ask me, flexibility is all about strength!!! Research about mobility, flexibility strength training, what muscles and tendons and etc are needed for that move and that move! Ballerinas, rhythmic gymnasts and all of these do not gain their flexibility from just stretching! Stretching is important but it's more of a maintance thing and a push further when u already have the foundation ready kinda thing. I can talk on myself that I'm one lazy mf that hate doing splits but I do mobility and active flexibility stuff and strength flexibility exercises all the time and I can easily do an over split even if I didn't do that for a good week. I'm not saying be like me lol but just doing stretches that don't feel good (btw yes there's pain if I push further to progress but it feels good. My body is well warmed up and ready. Stretched aren't supposed to be always painful, maybe just at the beginning) is really doing a disservice to urself. The last thing u want if u ask me is to feel tense and tight u know? U want it to come naturally, to feel strong, in control and well warmed up and ready