Taking a break from Tarceva - 1288508

I was diagnosed with stage 4 adenocarcinoma in Dec 2015 with one met to the hipbone. Another met to the hipbone was discovered in May 2016 and treated. I had VATS ULL to remove my lung tumor and radiation for the mets. I'm currently NED and have been taking Tarceva since May 2016 in hopes of staying NED. Due to side effects, the first and worst of which was horrible acid reflux, my dosage was reduced from 150 mg to 100 mg.
I am an otherwise healthy 43 year old female non-smoker who has struggled with the side effects of Tarceva--the reflux (which continues), frequent diarrhea, horrible fatigue, depression, rash, eye soreness, my nose is always terribly sore and constantly runny and my hair is now falling out and has stopped growing. Food doesn't taste the same, and my mouth is always sensitive. My doctor casually asked me if I wanted to stop the medication, but hasn't really entertained much discussion of the pros and cons of this. I'm scared to do so because I know the high recurrence of stage 4 lung cancer, but have no idea how successful others have been with this medication in staying NED.
I was also wondering if others have taken a "break" from the medication? My doctor implied that once one starts with this medication they cannot stop because they develop a resistance so it is a one-time chance opportunity.
I am growing weary of the cumulative effects of the side effects but also know it could be much worse and, am of course grateful to be NED, and willing to do what I need to do to improve my chances of staying this way.