Idk what to do

Im in high school and last year i played lacrosse and tryouts for this year are coming up and i dont really know why but i just lost all of my interest in it and all of my motivation to do it and i dont why and i dont want to tell my dad because he thinks “because i dont want to” isnt a good reason not to do anything and its not like i wouldnt be active if i didnt do it i can go on runs and go to the gym with my sister and stuff, but i just feel really confused and i dont know what to do. and i decided not to do band this year and my dad still brings it up 6 months after the fact and i have told him that i dont regret not doing band, i also have just felt sad all the time for a pretty long time now, not like a sadness that i am crippled by but it is kind of just always there. like whenever i wake up in the morning my dad just automatically starts off slightly below average and i really want to be the person that is genuinely happy and i have tried really hard to be like that but its really hard and i dont want to tell my parents because they think the mental illnesses like depression and anxiety and stuff arent real. 😫😫😫