My dad passed away two years ago...?

He died of cancer. I remember that I was very close to him. Much closer than I am with my mom. He was the one who would stop us from fighting every two minutes. The first year after his death, I was fine. I had some sort of peace that kept me from breaking down. But this year, it's like it just suddenly hit me. I'll start crying and missing him so badly I feel like someone is tearing out my heart. I've been fighting with my mom 24/7, my grades are dropping, and I feel like I'm slowly crawling into a shell. I haven't felt like doing much lately. And I also get very frustrated because I know I was close to him yet I can barely remember him. I can't remember the way he laughs, what he smells like, what he looks like (I have a picture under a pillow because I was afraid to forget his face). I only remember some funny moments, and that he helped me with math a lot. That's it. Is this some weird way for my brain to help the grieving process? By forgetting him? Will I recall things later? I'm scared. I don't want to forget...