To split, try lunges. Bend the front leg at a 90 degree angle and go as far forward as you can. Do both legs. Then get in to your straddle position and try to keep your back as flat as possible while folding your body forward. Do this every day. Also ALWAYS WARM UP BEFORE YOU STRETCH!!!!! I always wear socks when I stretch before bed, but if you are stretching before a class, try leg warmers over whatever shoes you wear. I have like 10 pairs of leg warmers haha. I have to stretch morning, before and after ballet classes and then before I go to bed. I got to NYCB so it's ballet all day, every day. So the point is to do a lot of little stretching frequently. If you need help, comment and I'll do my best to help.
Definitely stretch every day. I suggest you try a wall stretch. Put your legs in the splits position against the wall, and lay your back on the ground. This helps gravity pull your legs down. I do them for dance, and they help. Heres a pic and article: http://www.fitsugar.com/Stretch-Wall-Straddle-2031389 GL:)