Chevrolet: 96 Lumina wont start with key, newer cars, headach

Question
car just didn't start at grocery store.hauled it home and suspected starter so I replaced it for $130 and now realize the old one was probably good.Good battery.I can bump start it off the starter then it stalls right away as if no gas.Inside the car I have all kinds of power.Car acts as if the gear select isn't in park,but it is.In the dash,the stock security light flashes when the key is turned on,as it has the chev antitheft securty dodad.I cleaned the contacts on the key and tried to clean the inside of the ignition switch.I'm fearing that the ignition switch has gone bad but there was no warning of any problems,it just wont start.I'm very frustrated by this and if I could afford it,I'd just take it in.But theres alot of pride involved too,if ya know what I mean.Thanks for any help.

Answer
HI Barry;
       I know how you feel, as far as the ing. switch if it is starting to go , it will cause a lot of things to happen and it could short out the wires too , I would have it replaced a.s.a.p. and as far as the security system is it turned off, as that can also keep it from starting up, w/o a computor to hook it up to the newer cars are a bit of a headach in that way.