It’s excellent to become vegetarian!
Since I know that you’re in good health, this change indicates growth of your compassionate heart, rather than motivation by health concerns.
As you ease gradually into complete vegetarianism, you feel obligated to explain to your close friends and family, who tend to have very strong, albeit unspoken, objections. That’s why it’s important not make a big deal of it. You can show appreciation for the food offered by eating food that is appropriate. For example, the Sixth Patriarch used to eat only veggies cooked next to the meat.
Eventually, the people who really care will understand and learn to accept your diet preferences. It does make them feel better when they take special consideration for your diet when you’re a guest.
At times, you can’t eat vegetarian stuff that you like. That’s part of your retribution for obstructing others’ cultivation in the past. For example, as a result of eating onion and garlic, your mantra practice will be less effective for a few days until your body is rid of that odor. When that happens, do not get afflicted, and the next time you’re at the temple, bow (three times or more) to the Buddhas in repentance for such past karmas. You’ll be surprised at how your repentance will quickly make these eating mishaps less frequent.