02 neon

OK every time i turn my car on my belt squeaks so bad but stops and i already had the timing belt changed and when i stop sometimes to it starts squeaking. and it starts chugging very bad when i start to accelerate and it sound like something hits the hood and then the check engine light flashes on and off. idk what that problem is?

Those symptoms are mysterious to me too. Typically a loud screech when you start up means the alternator belt isnt tight enough, but I've never had one make that screech when it was being shut off. Maybe when it was idling, especially if the lights or heater blower were running. They draw a good bit of juice from the alternator. If its a loose belt and you dont fix it soon, the alternator drive belt will wear enough that it wont screech anymore, but it is likely to break because it will be 'slipping' a lot. The bolts to tighten the belt are not in a conveniet location, if you ask me.
If you live in a location where there are AutoZone or Advance Auto stores, they have a code scanner tool. It should be easy to have them connect it to the diagnostic plug under the dashboard, and read-off what codes your Check Engine Light has stored. Then tell us what they are - it may indicate what is wrong. At least what the computer thinks is not right.