Don't think you can do any 'better' than your lactose-intolerant cop-out.

This is going to sound Buddhist AF, but the problem is that in most cases, it's not the vegans introducing the conflict, but rather this conflict existing within the people who take offense.
They don't feel steadfast in their morals and often don't feel confident in their identity or self-worth either, so when someone comes along who does something they perceive as morally superior, then this confronts them with their internal conflict, which makes them feel like they're being attacked.

So, the two ways to avoid the conflict, as others already suggested, are:

• Never bring up that you're vegan, or
• Give them a reason why you can do the morally superior thing more easily than them.

That you're lactose-intolerant is perfect. Especially with many people not understanding what that entails precisely, you can say that you can't eat many foods anyways, so might as well go vegan. Or that it's even sometimes easier to just pick the vegan variant, as you'll know no dairy is in there.
This is still not easy to use as a cop-out. You'll regularly encounter people who might take offense, and you've got basically just two sentences or so, to defuse that situation. This is why many vegans stop caring, if someone wants to be offended. It's too tiresome to be a people-pleaser.

Not by asking non vegans. Vegans are the voice for the voiceless and you're taking part in a boycott that challenge peoples core beliefs. To be a good vegan is to push back and disturb social cohesion which people do not like. I'm not a vegan to make friends, I'm vegan to do the right thing.

you don't have to be good, and you don't have to apologize or explain your choices. the vegans who are jerks about it are right. their choices to act in ways which alienate them sometimes are their own. you can do the same or not. thanks for being vegan, either way

Yay for you! Nine year vegan here, I remember saying I would never do it either. But now meat and dairy aren't even things I think about, let alone miss.

There is no answer that will please everyone. It's best to treat veganism as a religion, as in an ethical framework that guides your actions. But just like religion, it's not polite to talk about it nor judge others for believing differently. You'll absolutely encounter people who feel comfortable for mocking your beliefs, including friends and family, but the best strategy is to smile and say you'd rather talk about something else. You can't control if others decide to be jerks, but tend your own garden and remember there is no profit in being argumantive back. Eternally change the subject and you'll rarely be accused of being preachy. Unfortunately there are those who take your meat as an inherent judgement of their own, but that is a dilemma they need to fix themselves.

Having said that, I applaud your choice and urge you to get b-12 supplements. A large chunk of the population is deficient anyways and while you adjust there is a good chance you'll miss some of the supplements added to meat products that mostly likely were your primary source.

I've seen a lot of hate towards vegans online, admittedly being someone who partook in that several years ago myself to a small degree.

Then you probably understand that the hate is primarily a coping mechanism because vegans propose arguments that question their lifestyle. It's a "them" problem, not a "you" problem.

If you value consistency, don't let a few jerks push you into a behavior that isn't true to yourself. Don't come up with fake reasons for why you neglect to partake in rituals that don't respect the rights of animals.

State your real reasons. This is also better for the animals. If someone then wants to start a discussion, you can still politely refuse.

I have attempted being ovo lacto vegetarian in the past, flexitarian and pescitarian, but never vegan.

My experience is that your motivation for not eating meat is why people care. If you do it for ethical or environmental reasons and not health ones. Then people will feel that you are thinking that you are superior to them.

Health one is the most accepted reason, because it is not an "attack" on someones values. Yes, it is ridiculous that people feel this way.

However it is more work having guests that have special dietary needs, and vegans and vegetarians are choosing it. People with allergies or religious reasons are not.

My experience is that the easiest way to get the most results with the least friction socially is to be a flexitarian. Eat vegetarian / vegan when you are cooking or buying food, and eat the meat and animal products you are served. That reduces your consumption of animal meat and products by 80-95% without the hassle.

I managed to be a flexitarian for 2-3 years, but gave up. Vegetarian I only managed like a month or two.

Also remember B12!