Why are my emotions random?

So im 16 and when it comes to promblems I just say whatever and suppress my own feelings( I dont wanna say I been through a lot but I have had my share of promblems) this lead to me not really feeling much of anything when it comes to situations, but recently after me and my best friend “broke up” I would only look at her and wanna run away or cry or just not look at her,its like the one person I open up to just leaves cause she thinks ima liar, on top of that last night I thought everything was good but I randomly got angry, and couldnt hold it back, so my dad asked me to do something and for some resaon we got into a fight, well I said stuff like what are you gonna do? ( he is bed ridden cause of a car wreck)..( I feel bad bout it).. And then I went in my room and thought about everything with my mom being an alcoholic and trying to kill herself when my dad almost died, how I told her she couldnt come home when she was admitted in the hospital for a 480 bal, (500 is the death limit) needless to say im now just really really depressed, should I expect random feelings to just burst on me? And what should I do?, btw I been dealing with “promblems” like the ones above since I was eight…I don’t know, im so confused and I don’t know what to do..help?