ontd advice needed!
how long should i put up with a boyfriend who is ignoring me?

background story - so my boyfriend of 3+ years is currently avoiding/ignoring me, and won't tell me why. i'm just wondering how long i should put with this for? it's been 3 days so far of him progressing from stand-offish to completely ignoring me. we're in different cities right this very moment (i'm home visiting family, and haven't seen friends/family from here since christmas or longer) and the last message he answered was if i asked him if he was wanting to break up with me, and he replied asking why i "always assume that" even if he's the slightest bit upset.

previous to this, we were living together for 4 months across the country from where i'm visiting right now. he's a few hours away, visiting his family. i went and stayed with him for a few days to see his family as well, and the day after i left... this whole drama began. on sunday, i'm heading back across the country to finish up my grad degree and he's staying here with his family, on account of not being able to find employment in the city we were living in together.

he's entitled to feel upset, if that's what he's feeling.. but i don't understand why he won't tell me what's going on? i'm trying really hard to not let his behavior sour the rest of my vacation at home because there is still a lot of people i haven't seen/things i want to do. i don't think how he's acting is ok, and i don't think it's fair for him to completely ignore me. it's really hurtful.

got any expereince or advice, ontd? thanks for reading :)