stressful day

I don't know why I'm having such a hard day. Everything, even the little things, just keep bothering me. I'm trying to study and I just can't focus. I ended having a fight with my husband when he called. I'm going through this resentful phase at the moment. He tells me things about prison and I look up the information out of curiosity (because half the time I'm not sure I understand what he means) and when he calls back he asks me to look it up because he has questions too. So when I tell him I already did and I couldn't find anything he goes on for the rest of the time basically wondering out loud about things and we don't really talk. It makes me angry because he spends most of our phone calls talking about prison, not asking about me or what I'm going through or what I've been doing. It's like I don't even matter. Trust me, I get that he's going through a lot, but so am I. I'm here with 3 kids (picking up the pieces of what is going on), the lack of money and trying to survive, and I just started a program to get certified in medical billing and coding so I can hopefully start a well paying career in a few months, but yet he doesn't even ask about that. He talks to the kids but he doesn't ask me how I'm dealing with all the stress. It's like its all about him. 
The worst part about all this is that I'm feeling guilty for getting mad and letting the phone hang up with out saying goodnight and I love you. I'm worried about him being in his cell feeling bad and not caring that I can barely see my computer screen because my eyes are filled with tears.
Maybe I'm not cut out to be a wife at all.