Headlight flicker on my 2000 S10 ZR2

It could all be related, and the principal suspects are the Alternator and the Battery, both together. If the lights are getting brighter when you accelarate, that is a clew that there is a problem with your charging system. Hve them both checked out and find out how old that battery is. If it’s around 3 or 4 years, start thinking of replacing it. That is about the life expectancy of most batteries today.