Advice? My mom & my bf

Hello, I wanted to ask for some advice since this has been something that I've been wanting to do since I first went out with my boyfriend.

My boyfriend asked me out on a lovely Wednesday afternoon. November 11th of 2017. I was so excited since he's been there for me since the time we started talking in September. Seems like a quick relationship, however we seem to be getting along perfectly well. We often see each other every Mondays and Wednesday's. He lives in Downtown where as with myself I live by the beach. It's basically an hour and a half for him if he were to take a bus, since he's waiting for his driver's license in order to drive again. Anyways, he's a sweet man, always caring to the ones who care for him and is deeply in love. During my college applications, through my struggling times with my friends, school, family, financial problems, and the pregnancy scares that Ive been experiencing the past month; he was there. He would always make sure that I'm okay, that I'm happy and not stressed. More about him, he works and use to go to school but he's taking a semester off in the meanwhile. He loves his family, loves his friends. He's always giving back to the ones he knows that deserves it. Basically he's a great guy, loving and caring. My problem is that I haven't told my mother about my relationship with him. She knows that I hang out with him every Monday and Wednesday but she doesn't know that I actually have a serious relationship with him. Probably im overthinking but I feel like my mom won't tolerate it I don't know why. I come from a Mexican family and so does my boyfriend. However my mother is pretty judgmental when it comes to people that are in the Mexican state where my boyfriend is from. I only told her where his mother is from, not his dad since I never asked. But just knowing that my mom is iffy about my boyfriend as a friend scares me to tell her about the relationship.

She expects me to date a light skin Mexican or a Caucasian. Don't get me wrong i don't judge but all my life I have always thought about caramel skin Mexicans are what I die for. And that's how my boyfriend is. But my mother always rubs it to my face how she wants me to have a light skin man in my life with colored eyes and you know all that stuff. Like I said I don't mind but that's not my type. And that's what makes me scared of my mom. My boyfriend has long straight hair, he's tall, and pretty big in size. I don't mind his appearance at all. I still find him adorable and cute. But I know my mom just by looking at him isn't convinced. She has met him once and has a quick conversation with him since they both talk A LOT. I mean I assume that she was okay? But I'm not sure.

I want to tell my mom how sweet and caring my boyfriend really is. That he's willing to help anyone no matter what. He's willing to be there no matter what. I'm not sure how to tell her since when she got back from Mexico last week she saw me in my boyfriend's sweater and laughed over the fact that was my boyfriends..

I'm not sure. I want to tell her before my birthday since he already called off for that day. But I don't know how since my mom is pretty scary in my opinion. How should I tell my mom about my boyfriend and I's relationship?