is it wrong to be upset about this?

So this morning I got very upset when talking to an old friend of mine, I haven't talked to him in a very long time and he asked a few questions about how things were going and stuff.. well we got onto the topic of pets and I had a cat that died what, 6-7 months ago? I don't know.. it was a few weeks after my sophomore year started.. well I told him how he died.. it was my fault and I hate myself for that. But its the truth. And he responded with "it's a good thing nothing else happened." And I know I didn't explain the whole story to you guys but do you think it's right for someone to say that? I mean death is the worst possible outcome of any situation really, so what's so good about that? 

This isn't even the end of the story, so I get mad and yell at him, then I just stop talking to him so I don't get to mean and feel bad later.. well my uncle asked why I was so mad and I told him why and he said "you should just get over it, cats come and go." Then he laughed at me, he LAUGHED at me. It's like if I said "if you died I shouldn't be sad, people come and go." I cared so much for that cat and it took so long for him to trust me.. and then we had to put him down, once he trusted us we killed him. I can't get over that. I can't, I did something so wrong to that poor cat, I just wanted to show him some love.. because he didn't get much in his life... 

..do you guys agree with me..? 

(Oh I'm so emotional.. I started crying a bit..)