Not vegetarian, but have some related experience.
The problem isn't vegetarian vs. non-vegetarian, the problem is moving away from whatever diet you grew up in. There is a ton of "a meal looks like this" knowledge you don't really know you've absorbed, but changing it means you have to learn new things. This is especially true about achieving overall reasonable balance.
Two suggestions. 1) Look at major international vegetarian cuisines (e.g. Buddist, various Indian regions, some middle eastern) and learn some basics, practice until they are easy. 2) Find a broad range cookbook like "How to cook everything vegetarian" pitched and your comfort/skill level with cooking.
If you are really worried or confused about dietary balance, read something like "becoming vegetarian" or the like, a nutrition book rather than cook book. Actually, read a few, it will help you avoid the diet fad issues that plague food & nutrition. Question anything you feel sounds extreme.