The idea was to lose weight and lead a more active lifestyle, but you specifically wrote down that your resolution was to "go vegan". Now you move more sluggish than ever with your stumpy sauropod feet. And your neck alone weighs more than you ever did (or ever could) as a human.
Being an anthro brachiosaurus isn't that bad though! You can't fit through your front door anymore and your reptilian face scares most unchanged humans away. However, you can effortlessly reach and grab leaves from high branches using nothing but your mouth, and they taste better than any bagged salad from your local supermarket!
Basically, you won't be regretting your poorly-worded resolution at all over the next twelve months.