So many problems! I dont know what to do!?

ok guys, here we go. i bought a 10 month old "project" filly last month. I bought her really cheap. When they sold her, the people said she had gotten kicked on the trailer, she had a lump on her back left leg. right on the muscle. I didnt like the look of it, but i thought it could have been what happened. The lump has not gone away! And i cant touch it because she is wild and LOVES to kick. i can get close now, cause i have worked with her so much, but i dont know what to do about it. Any comments? Advice? Thanks everybody!