Car won't start. The key ignition won't crank over.

What is your question?

My 02 Chevy Malibu has been on some BS. Where I put the key in the ignition but won't crank over. It's like the ignition switch is stuck.. this is the 2nd time it has done it.. so everything my back tire behind the passenger side gets low or something in it. My boyfriend will fix it and then it starts acting up. Like some days it will miss fire. Plus when we got the car the anti theft light was on for a while until a buddy of ours took it off. Like what's the problem for the key ignition not turning on? I need some help on this.. I get by couple different people that it could be fuel pump, the whole ignition, and so much other parts of it.. Please can someone answer this question about why the key ignition won't even crank over? You can put in the key but won't turn it on or start the car.. Any ideas on what it can cause it to do this?? Please help me..

What makes this problem better or worse?

It's worse when fixing the back passenger side tire..

How long has your 2002 Chevrolet Malibu had this problem?

This is twice it has done it this month less than two weeks apart from the first time it did this