It takes an enormous amount of courage to be sober in a world where a drug is so socially accepted. Imagine if that drug were heroin; there’d be a national outcry.
One of the most common reasons for relapse is succumbing to pressures of those who become obsessed by what you choose .. or choose not to .. put into your body.
Most people who continually push you to drink usually have their own reasons for wanting you to fail. It could be that they have alcohol issues themselves or don’t like/want you to change.
But you are stronger than that.
Politely tell that person that you do not wish to partake. Kindly ask them to refrain from offering alcohol as you do not wish to poison yourself. Be prepared for a fall out but do not fear. If someone cares about you, they will respect your decision.
And remember, the majority of people are in awe of you. You are achieving something many people will never do.