I like the layout to this story. I think the purple goes well on the white and with the background. I also like the fact that you didn't use a banner for the story. I think that adds to the layout. My only complaint is the size of the font. Perhaps it's just my computer - I use Google Chrome - but it's extremely tiny and hard to read.
I like that Gerard is slamming the cabinets shut and slamming the pill bottle down on the counter. Kind of made me giggle :3
Some errors I noticed are that I'm not too sure if those semi-colons should be just that, or should be commas. Personally, I'd use commas.
You also put: Gerard takes a deep breathe. instead of breath.
'This relationship is dying.' Bert starts to think but quickly shakes his head. "Never say die." I really loved that line. :)
"I just want him to realize that he's betrayed me. He used to call me his addiction, but I now, he's chosen the wrong addiction." I would either get rid of the "I" in "but I now" or change "now" to "know". I was quite sure which one you were going for there. Regardless, I like this line a lot.
I think it's cute Mikey hugs him before he leaves :3
I won't lie, I felt like you were going to write "Never say die." at the end for some reason XD
Overall I do like this story. I also like the pairing, and that you decided to make Bert the one with the drug issues rather than Gerard, which I've seen done before, so it gives it a refreshing twist.