Just do your best, mistakes will happen. My wife and I have been fully vegan for 12 years, but she just got a gelatin medicine. Sucks, but the alternative is her health. We'll find an alternative hopefully soon.
Back in year one, we cheated and had a special ice cream, but it wasn't worth it.
If you can afford purple carrot for a few weeks, you can learn some new meals.
When we started, we didn't have many 'vegan alternatives' for meat, cheese, ice cream, mayo, etc, and we were much healthier eaters. Now we just use Beyond in our chili and call it a day, but it was better when we used TVP. It would be good to try both vegan meals, and substitute versions.
Other than that, just remember why you're doing it. I can't stand the thought of hurting animals, so I could never go back. Some do it for the environment or health reasons and those are probably easier to give up on, but find a passionate reason to push you over that ledge.