Life after losing one of my little sisters

I just lost my 17 year old sister last year in November to suicide and I’m 20 now and every day since then I just feel like I failed her as a big sister and it life is just miserable. Anytime I have anything good going I just think about how I could’ve been there for her more and it makes me feel like I don’t deserve anything good in life. It’s truly scarred me and I know this November coming up is gonna be hard so hard for all of my family. I really just live life like a drone now I go to my job then pay bills and live paycheck to paycheck. Only time I really actually enjoy myself is when I smoke weed and I never smoked before until I lost her so it’s kinda crazy cause I thought I was never gonna smoke. It’s really crazy how life just goes on and since I’m an adult now I gotta just keep going. I really only keep going for my loved ones. I try to seem like I’m happy so I don’t worry my family but I’m just really not and every day I just wonder when is it gonna end because I’m not strong enough to do it myself like my sister was.