I'm not sure what you mean by bad. I have stage 4 NSCLC. I've had 4 rounds of chemo ( not as bad as I had feared) lots of nausea, stomach cramps, threw up a few times, diarrhea and lots of fatigue. The good news my tumors are shrinking so it was a 100% worth it to me. Best of luck!

Nathalie,
I didn’t need chemo for my lung cancer but did have 5 rounds for breast cancer. I’d leave work early on Thursdays, have my treatment which lasted 5 hours, go home and collapse and back to work on Friday. Somewhat nauseous Saturday and Sunday and back to work on Monday. All in all, it wasn’t too debilitating as it was controlled by compazine. The zofran actually made me more nauseous than the chemo. Also, losing my hair was liberating. Just threw a wig on and no bad hair days.
If your dr thinks you should have chemo my advice is to go for it.
Lois

Chemo will not kill you. The cancer will.
Chemo probably will not cure you, but it can add years to your life. You can probably do most of the things you normally do, though it may take a little more effort.
Don't listen to people. Listen to your doctor. Find out what chemo agent(s) will be used and look up the side effects. The list will probably be long, but most people only experience a few of them.
Stay positive!
It's the best thing you can do for yourself!
Tony

I didn't have much trouble with chemo. Had 6 rounds of carboplatin, pemetrexed and keytruda. Now on keytruda only maintenance. Stage 4 nsclc adenocarcinoma with mets. Mild nausea controlled with Zofran, some diarrhea controlled with meds, and some fatigue. January will be a year since diagnosis. Diagnosed at stage 4 with mets so I definitely lived more than "months". Stress can make side effects worse. Just now losing hair due to an uncommon side effect from keytruda when your thyroid is wonky (Graves disease). But really, no it wasn't anywhere close to the horror stories you hear. Everyone is different and dome people don't get any side effects at all! You don't know how you'll react until you actually do the chemo. You can't anticipate which, if any, side effects you'll personally experience.

Every cancer treatments are dangerous depending of personal cancer profile.