I've lost motivation and its my birthday...

Hi! (16 M) here, I turned 16 today, a total of THREE people from my school wished me, none of my old friends, with whom I thought I had good friendships with, wished me. I've also set high af expectation since when I was young, and my parents expect me to continue getting 24/25 in math tests. I've come to a point where I've just lost motivation to continue working. Sometimes, the fire ignites and I try-hard for an hour or something, but then someone interrupts me, and the flow is gone.

My parents also haven't bought me a single thing since I was 8 or something. I bought my father a diary for his bday, and a diary and a shelf organizer with my own money for my sister's, but all I've received today is a 10-minute talk with parents (and my father forgot I was 16, he thought I was 15), and scolding since then. "Massage my back" or "Give me that" or "Why did you remove this", I am really getting fed up.

Because I have to focus on studies a lot, I don't have time for other stuff, like playing, to keep myself fit. So, I've started going to the gym for like 30 minutes a day. That's prolly the only thing giving me motivation, and making me feel better.

The main thing is I don't fking know how to say no to others. I put other's happiness above mine, and thus, if I make others happy, I feel happy... sometimes. For other stuff, I undergo really hard things just to keep other people happy.

I don't fking know what to do. Please guide me :)

- Random stranger (I accidentally spelt out star instead of stranger, the sky is the limit)

Hope your day goes well!