Q: Dash lights are on and have issues with the battery and the transmission.

My e46 325i is having issues. It starts with battery light coming on and then brake lights, traction control lights, abs, check engine light. Pretty much every light. When driving, it's like it downshifts hard and my transmission goes into safe mode with exclamation point next to the gear indicator on the dash. I've replaced alternator and when it left the shop, everything was charging and doing good and about five miles later, back to same old stuff. Sometimes she fires right up, then other times it acts like a dead battery and after I turn the key off, there is a weird noise from under the hood somewhere sounds like an engine or some kind of whining noise almost sounds like it's in the dash or firewall area. I've ordered a new computer for it and I've had it hooked up and it read something about my drivetrain control module but I'm still not sure if that is the problem and was wanting to know if I'm headed in the right direction or if this is a common issue or what.

My car has 187086 miles.
My car has an automatic transmission.