I've always drank (15yrs or so) about 3-6 beers a day 3 to 5 days a week. what kind of side effects can i expect if i totally quit.?

Beer belly plus: Besides getting a bulgy waistline, you can expect possible liver disease, neuropathy, cognitive problems. Most likely, quitting, which will in long run be a good thing, may be accompanied by withdrawal (including delirium tremens) but more likely intense psychological craving for beer. Of course, things may go completely smoothly for you if you quit. Let's hope so.

Few or none: The fact that you don't drink 2-4 days a week is encouraging & means it is unlikely you will have many side effects. You may feel slightly anxious at times.There are natural calming remedies like holy basil, l-theanine & GABA (combined in products like theanine serene from source naturals). A good b-complex can reduce cravings. Exercise & meditation reduce anxiety & thus help make quitting easier.

Drinking Alcohol: You may or may not have symptoms like anxiety, shakiness, nausea, sweating, etc within the first 24-72 hours after your last drink. If you're actually under-reporting the amount or frequency, your symptoms could be more intense. I'd suggest talking with your physician so that you have help with this. Also, you'll need support for changing lifestyle to a non-drinking one -- aa can help.