How can I get through this

I’m 21 F , I am tired and daily I feel like not physically killing myself .. but I find myself hoping it all ends . I have nothing excited to be about in my life . Most of my nights are spent me crying myself to bed because I just feel useless like I’m just existing.. but I have no real inspiration or thrill to life anymore. After experiencing two tough deaths recently one last year of my boyfriend and the other one in 2019 of the woman who raised me my grandmother. They past 2 years I was diagnosed with mild depression and anxiety I was placed on medications but I discontinued them after one week because I felt I could defeat the depression and anxiety. Which pretty much I have learned to control my anxiety but depression sneaks up everyday . Reminiscing about my bf and how I feel so alone in this world . I’m in school for premed but I lost all motivation and I’m barely hanging on by a finger nail. I just feel like it’s no winning in my life and it’s feel with so much pain and trauma sometimes it’s unbearable for me and I just want to end it all. I’ve been going to church more , praying daily and trying to stay fit .. but I’m still hurting deep down inside .