It was super easy for me to get everything I need. I was 15 when I went vegan, and likewise, my mom was worried. So I just told her I was only doing it for lent (but I had no intention of looking back). Over time my mom got used to it, and she even went vegan for a year (sadly she went back because we had a trip to DR and she was tempted). Just try to educate your mom on what veganism is and the benefits it has. Talk to her about the dairy and meat lobbyists in congress. Make her aware of the meat and dairy propaganda. Also make sure your diet is diverse. Don’t eat the same things over and over again. Make an effort to try new foods too!