Help with Sims 3 glitches ?

I've had this game ever since it came out and it's been fine but the other day I downloaded a new hairstyle from the sims 3 official website with the free 'sim points' I got for purchasing the game. Yesterday was the first time I used that hairstyle in the game and in a couple hours of playing time it started to glitch up, one of my sims (The one with the new hairstyle) had their head disappear! I thought ok this will clear up if I give her an action to do such as making her take a bath but no, she still had no head AND she was doing everything in martial arts clothing, bathing, sleeping in them ect. I started playing thismorning again and now theres another problem, both of my sims can't sleep, I task them to sleep but once they get into bed they then sort of jump out and appear at a random spot, the kitchen, garden ect. I have no idea what to do and it's getting really frustrating. I've heard that these downloads can make games glitchy if you download too much (I however have only downloaded 2 things.) but surely from the sims 3 website it should have been ok ? I downloaded 'riverview' when I first got the game off that website and I had no problems .. I'm confused. Please help, I'd love to be able to play this game normally again!!..