<human>: Give me the gist of the text in a nutshell

As the title read. He was at some point my best friend but suddenly ignored me for months. (I'll call him C) Two days ago, C messages me on Facebook and asks me to call him. I'm a very busy person, my three siblings have been in my care for the majority of almost two years due to my mother trying to finish nursing school. I had been busting my ass to ensure that everything was going smoothly. Cleaning, cooking, getting kids off to school, homework and so on. Haven't had much free time until recently when she graduated. And the free time I do have, I'd like to spend with my boyfriend(19).

During the time that C had been ignoring me, his step mother messages me on Facebook, she explain that C had gotten too "emotionally attached" and was angry that I was with my boyfriend. (I'll call him J) J and C have only ever met once and the tension in the room when this occurred was now completely clear.

Back to C messaging me, I told him that I would when I had the chance. He messages me the day of my mother's graduation with "Guess youre too busy as usual, you don't have to call, its good. Just dont act confused. It's obvious I'm being blown off. Again." I was so off put and so angry that I didn't know what to say. He then goes on about how I've been blowing him off and saying I can't hang out but he sees me post things out of the blue. I'm busy a lot but I'll leave Reddit and Facebook open to keep myself from stressing out, I'll sit down for a few minutes and back to what I was doing. But sometimes, I like to be alone and this just seems over bearing and outrageous. I suppose it's my fault for feeling like I was sparing him when I say "I'm busy", when I really just don't want to hang out. 

I want to fix this, he's a great friend, I just need to know what I should do. What should I say? Or if I should even try to redeem this friendship.
<bot>: Friend ignores me completely until two days ago, gets mad that I don't have enough time for him. Makes me feel like a crappy friend, so I kidnap his cat.