I (28F) found out my aunt (50s) is my biological mom.

My childhood was awful and I spent most of my 20s with a serious and untreated mental illness. I have a learning disability due to head trauma and now that I'm in college I'm having a ton of difficulty. I'm fine at working, and am a bit over an overachiever when I'm actually in the workforce. But it takes me hours to even remember what different Greek letters mean in my math-related courses. That sort of thing.
My grandma moved out of her house and we had a ton of family pictures to go through. In it was a picture of my aunt with a guy. She was pregnant and the date on the back of the picture matched to right before I was born.
My mom doesn't have any pictures of herself during any stage of her pregnancy despite being married to my dad at the time. My whole life I've been likened to my aunt, and I don't look much like my mom or dad at all. Boyfriends always comment how different my mom and I look, and she's easily put in a bad/competitive mood because I get compliments when we go out.
I kept the photo and later asked my grandma about it. She's a straight shooter. She told me mom aunt was not in a stable career and my mom and dad were stable. They adopted me when I was a few months old. And I was a kid and wouldn't understand. And then I was a teenager who was angry at everything. And then I had a mental breakdown and likely wouldn't have had a positive reaction. And then because I enrolled in college and had mentioned a few times how stressed I am.
It's more frustrating because I'm not able to have a serious conversation with either of my parents (about anything). I don't have much of a relationship with my extended family because of my mom, even though we all get along really well at family gatherings. I don't reach out much because I don't really know how, and at this point I feel like it would be weird. My dad isn't close with any of his family and though I'm friends with my cousins on Facebook, we don't talk. The only reason my dad knew his sister died was because one of my cousins reached out to me.
My aunt has a family now and she's such a good parent.
I have no idea how to process this and I'm in school full-time and work 30 hours a week. I barely have time to study enough and don't know where I would fit in time to see a therapist. And I only recently started working so much, and my Medicaid is more than likely going to run out. So I likely won't have the money anyhow.
I asked my grandma to keep it to herself that I know, but I know it's created a huge burden for her and it's unfair to ask it of her.
I have no idea how to bring this up, or who to bring it up to. My mom doesn't even know what major I am despite me being a sophomore. She doesn't remember what foods I'm allergic to, and I don't talk to her much because I'm never doing anything right. My dad is only just getting emotionally stable after a few years of being really depressed (and only talking to me about it), and he takes everything so personally and requires days and weeks of reassurance that he isn't a terrible person. My sister is special needs and wouldn't be able to understand.
I'm more sick to my stomach that I had to endure my childhood and I don't even have a relationship with my aunt. And now to see how good of a parent she is, is sort of a kick in the gut.
I'm not sure where to turn.
TL;DR: found out my biological parent is my aunt, who I am not close with. I'm not able to talk to my parents about it, and I don't know but to ask my aunt. It feels like I'm drowning.


Source.