crank no start after it got cold out side?

i tried to start my car after it got cold out side an it tried to start a few times which its hard start always the car trys but when it started it sounded like it flooded out an dies now i cant even get it to do that it just cranks the battery i had tested an its good how ever trying to start the car now the battery seems to wanna die quickly iv checked the fuel pump is kicking on when i turn the key to on position i just changed all my spark plugs the crank shaft sensor is working because the rpm needled moves as i try to start it i checked the rely under the hood in the fuse box by putting my finger on them as a friend tried starting the car an i feel the rely clicking on all of them how ever i dk where to start next i know my spark plugs are covered in oil again an the fuel injectors need checked as well as the throt body sens the cam sens an the maf sens just not sure what one to start with an if there is a way to clean them to see if it would work long enoughhh to get the new one now prior to all this the car had a smell of gas an Exhaust had a flex hose on it that had came apart from the car it was cut off an straight pipe welded on an the smell got worse after that when i sit at a stop light i could smell it in myu car with windows up the car also has an alarm on it i wasnt aware of this i got the car last march an about amonth ago i unlocked the passenger with the key an the alarm went off scared me like nop other i went to driver door an put the key in the door an it stopped there is no key phobe or keyless entry that came with it an the alarm has done this now a handful of times the driver door handle broke off so im having to go through the passenger door so i was wondering if maybe a security thing has triggered any help advice is gladly appreciated im a single mom of 4 kids an this is our only car im pretty mechanic handy an fix my car my self from help with sites like this an youtube if i didnt havwee these options id be lost so again thank you for it makes my life easier an saves me money