Why do I get mad so easily?

Lately, I’ve been getting mad at all the little things and it’s usually aimed at my boyfriend.

He’s recently got back into an old hobby (bike riding) and everytime he tells me he’s off to do his riding it’s like a timers ticking, counting down to when I’ll explode. I feel ridiculous thinking that he chooses his sport over me but sometimes I can’t help it.

We’ve been together for 8 months, lived together for 6/7 and never once spent a day where we’ve not seen each other. I don’t work so I spend all my time at home on my own waiting for him to get back like a lonely dog, but when he does he doesn’t feel like doing anything or sometimes even talking, which I obviously lack, for him to then go and ride on weekends because he needs his own time. I understand that he needs to do his own thing but I need his attention since I don’t get any all week.

It’s getting really hard.