My hip muscle is so tight, how can I loosen it?

Every time I do the middle splits, sit criss cross apple sauce or do a butterfly, my hips hurt (in a stretching way) I am a dancer and I need to gain my middle splits over the summer. Even when I sit criss cross (Like you did in kindergarten) it hurts in a stretching kind of way. Is there anything thats wrong with my muscles? Or is it just really tight and I need to take my time stretching it. My middle splits are not even close to the floor too. So if you could offer me any tips to help progress my middle splits? Thanks