I feel like rubbish today

I think I have depression, I'm not sure but I constantly feel like total shit. I don't want to do anything, I don't want to get up, I don't want to do anything that used to make me happy and I just feel like If I'd died- I wouldn't actively do it but I feel like I'm very passive about it; I wouldn't be happy to but I wouldn't exactly be sad either?? This isn't always, but today has just been a really awful day.

Sometimes I look forward to things and I laugh and chat to my friends but in the back of my head I know that if I was hit by a car- I'd be sad but.. Not properly? Most days I ignore it and some days I feel completely different, think today's just been a really horrible day that's been building up for a while.

I genuinely don't know what to do, I can't talk about it with my family and I couldn't dump it all on my friends either, I think by bottling it all up I've made it all worse. ( sorry for the shit grammar but I can't be bothered to fix it)