You married this man and didn't talk about what religion the children would be before you married him?
It seems that you don't actually feel much affinity towards your own religion, so you have downplayed the baptism in your own mind, thinking you could minimize it in his mind, but it didn't work. If you didn't really think that baptism was all that important, did you have it done because you want to hedge your bets and make sure your kids have a chance of going to heaven, just in case that is what baptism does?
You can try to explain what you think to your husband. Maybe he will get over this, maybe he won't. You haven't said how you two are raising the kids. How strict in Hinduism is he? Does he allow the kids to eat meat?
He married you in a church, so he must have some flexibility. You aren't planning on getting the kids confirmed, so you have some flexibility. Just tell him point blank that you aren't going to make your kids catholic, but you did have them baptized in a familiar setting so that they could have a blessing that you had yourself.
I do think that you two need some counseling because you have to come to an agreement on how the children will be raised. It's late to be saying this since you have more than one child, but if they will be raised as vegans, you MUST study this diet and make sure the children get proper nutrition. Vegan diet is hard. You aren't Hindu and probably don't know how to do this - mothers teach their daughters what to cook in Hindu/Indian culture, and your husband probably doesn't know how to teach you that. If your husband doesn't require a vegan diet, that's evidence of more flexibility. Just hope that he will think in terms of "catholic lite" when you try to explain that the blessing of baptism doesn't mean that the children are confirmed or that they can take communion. Remind him that they won't be taking CDC classes, which is the only way they can become confirmed.
And finally, tell him that his friend who thinks that baptism makes people catholic doesn't know your feelings and thoughts and experience with being Catholic. Pretty much every Christian religion baptizes - either babies or adults. But baptism doesn't make one a Christian - it's not enough to do that. There's more to it, and hopefully once you take your husband through the entire program of catholism to get to the point that you can take communion, he will understand that being baptized doesn't make someone catholic.