Vegan help

Asia

Hey guys! So I need some help with my vegan choices. I want to know a better way to become fully vegan. I was vegan before for about 3 months and I got really sick and lost weight that was at a fast unhealthy amount and realized it was because I completely cut off foods to not eat cold turkey. What’s the best way to become vegan healthier and what brands have good vegan foods but are also a good price range ?