Crack in Expansion Tank

I'm completely new to this forum and all this stuff so please forgive me if this is a dumb question. I was driving back from work today and everything was going fine with my car. it wasn't running hot or anything. I pulled into my apt put the car in park and turned it off. I got out of the car and out of nowhere I hear this pop noise and I look down underneath the car and its a steady flow of water coming out and then smoke starting coming out from under the hood. So I wait for the engine to cool down (about an hour later) I go back out and crank the car. Its not running hot or anything I look inside at the gauges and the ant-freeze sign turns on. So I turn the car off and wait about 30 minutes for everything to be cooled down when I open up the cap to the expansion tank to pour some anti-freeze and water in and as fast as I pour it in I can see it coming out the side of the tank out of a pretty big crack. My car has been running fine with no obvious problems. it has 129,676 miles on it. Then I started thinking about it it was about 2 weeks ago the fan or the ac and the heater went out in my car. I could still feel warm air or cold air depending on whether I had the heater or the ac on but it wouldn't blow out of the vents unless I was driving down the road. Basically the wind of me moving was pushing the air threw the vents. I've been out of college for a total of 4 months just moved to a new city for a new job and I'm pretty broke right now after the cost of moving and starting out this new job. SO I was wondering if any of you guys had advice on my situation with the car trying to spend the least amount of money that I can for a month or so until I start getting my paychecks and can afford to take it in and get a complete check and tune up. Any ideas of what my problem could be? I'm hoping it's just the expansion tank but I'm also a novice when it comes to cars so I'm just trying to get as much info as I can on forums to help me... Thanks for the advice in advance that any of you guys can help me out with......


P.S. I have a manual transmission and I drive a 2001 330ci