and 
(albeit a day late).
I suspect that most teenagers won't understand the importance of Mother's Day... until they become parents themselves. To us, it's a day where we either miss our own mothers, or feel taken for granted in whatever small way, by our own children - which isn't always their fault, because they're children, and need us for the small details in their lives! And even if our daughters become mothers, and suddenly realise how awful it makes us feel to be taken for granted (because they're then the ones being taken for granted by their own children!), our sons? Might never "get" it.
I'm a lone parent and have spent many a Mother's Day without even a paper card or a verbal "Happy Mother's Day, Mum!" from both of my children. This year, I had no choice but to go NC with not only my own mother, but my daughter, too. Which leaves my 14 year old son - who spent the day as he spends most weekends: plugged into a game on his 'phone with his headphones on. Luckily, my brother thought about how shit I might feel, and took my son out on Friday evening to buy a plant for the garden. But I spent my Mother's Day clearing what used to be my oldest child's bedroom. It's just another day, now. It has to be, else some of us would go down that path of self-pity and wallowing - which doesn't do anyone any good!
"... you are stressed and exhausted, and that makes you over-sensitive." and "You need some time to yourself."
^^This, OP. You need a break from the mundane chores that motherhood brings with it (I get the SN, because my daughter has some issues, too, which I've spent the last 22 years dealing with singlehandedly, and it is exhausting and lonely - even when you have someone else, like your DH, to share the mental load with!), and I hope you found some time/space to just breathe and think "it could be worse", yesterday.