Splits Help

Hello...

Let me start out by saying this. I am NOT flexible at ALL! I have been a martial artist for 14 years and throughout all of these years, I have always had a huge amount of trouble when it comes to flexibility. However, for around the last 3 or 4 years I have been working constantly on my flexibility, mainly, just accomplishing the splits. Unfortunately, I still have not accomplished this.

This is my daily stretch routine I have been doing for the past few years. It has helped my splits go from about 90 degrees to around 110 degrees, however, as of recently, progress has slowed a LOT.
-30 seconds of front splits (each side)
-30 seconds sitting on the floor with a leg extended reaching for it (each side)
-5 minutes of doing the splits up against a wall with 5 lb weights on each leg stretching further every minute
-30 seconds to 1 minute of butterfly stretch

If anyone has any more ideas on things I could do to help me accomplish the full splits (180 degrees) please let me know. I would love something more to try and hopefully to work.

Thank you very much!