I'm not a vegan, but behavior change (if you want to change) is most effectively accomplished with smaller, incremental changes. If you try to make huge, sweeping changes from the start, there's a very good chance you won't stick with it. Vegans expecting you to "just" eliminate all animal products on day 1 is very unrealistic.

For the animal products example, you could reduce (not eliminate) consumption of one thing at a time. Start with one meal per week for a week or two, reduce the portion of meat or other animal product you want to eliminate by 1/3 or whatever you can manage. After a week or two, you reduce the portion in another meal. Give it a week or two. Then another portion. And another after that. Etc.

If you can do more, then try it out. If you feel like you can't reduce one week or another, don't pressure yourself to do it, just consider it a victory of sorts that you didn't eat more. It's a marathon, not a sprint. Taper the dosage, don't go cold turkey.

I haven't done this for animal products, but I have done it with alcohol and prescription medication. I can't guarantee you'll see success, all I can say is that it worked for me and others I learned from.