I need to break my lease asap, I dont feel safe!!!!! Moving there was the WORST mistake I've EVER made!!!?

I moved into my apartment in November. In Dec. my fiance slipped and fell on the ice (no plowing or shoveling done in days!!) broke his hand and was out of work for months. Our landlord still hasn't resolved this. Our house has been broken into twice, ALL of our clothes, CDs, and our engagement rings were stolen. We got police reports. There was no sign of forced entry. Our apartment "managers" are young punks that never return our calls for maintenance, and to top it off have keys to everyones apartment. I believe thats who has been in our house. Then last week 6 male mexicans (Im not racist!) moved in below me. I have a 9 month old daughter, and they constantly play loud music, scream and yell and fight, and are very rude. I usually work on Mondays, but today I took off. My car is parked in the garage. 4 times someone knocked at my door and no one was there. I think they were checking to see if I was home, to break in again. I'm so scared and feel so unsafe!! What do I do?!