I'm getting the booster because I want to do all I can to protect myself

Good for you. I respect your right to do what you feel is best for you and your family.

to prevent the spread of a virus that might kill my parents

I don't think boosters are going to prevent the spread of omicron. If I am tested weekly and continue to wear a mask whenever practical (ie indoors outside my own home) my chances of spreading covid if I become infected will be low. I do take the covid virus very seriously. However, as far my family is concerned half of them never got the first round of shots (even though I tried to convince them to do it). I have to beg my parents to wear masks when we go to crowded indoor places. I'm so exhausted from fighting with them over covid that as far as I'm concerned their protection is up to them. Yes I will I be devastated if I infect them. However, given their behavior they are more likely to infect me.

Hopefully your situation is different and your family and friends also take precautions. Sorry for the rant I'm not in the greatest mental state regarding covid at the moment.