Plus 44 - No It Isn't Lyrics Meaning

For starters, this is definitely, 100% about the end of blink-182 and Mark's relationship with Tom.

First verse:

"Please understand, this isn't just goodbye, this is I can't stand you" - speaks for itself.
"This is where the road crashed into the ocean, it rises all around me and now we're barely breathing" - talks about the sudden ending of blink-182.
"A thousand faces we'll choose to ignore" - the "thousand faces" refer to blink-182 fans.

Chorus:

"Curse my enemies forever" - Mark never wants to speak/hear from Tom ever again.
"Let's slit our wrists and burn down something beautiful" - blink-182 is the "something beautiful" in this line. I personally think that this line is saying that they were careless about "burning down" something as "beautiful" as blink - they're just going to be sad, depressed, and destroy blink-182.
"This desperation leaves me overjoyed, with fading lights that lead us past the lives that we destroy" - by ending blink, they've destroyed the lives of blink-182 fans. The fading lights might refer, if you were to be deep, to their guide in life; when blink ended, their guide, or "light" that was leading them through life, faded. Mark didn't know what to do when blink-182 ended because blink was his life.

Second verse:

"I listen to you cry, I cry for less attention" - quite self-explanatory. Mark listened to Tom cry, and he implies that Tom cried for attention, or turned on the water works to get out of tight situations.
"But both my hands are tied, And I'm pushed into the deep end" - the ending of blink-182 was inevitable; Mark couldn't do anything to stop it.

"I listen to you talk, But talk is cheap" - this may be interpreted two different ways. The first, Mark listened to Tom all through blink's career/the final months of blink talk about how blink was the world to him and Mark and Travis meant a lot to him, but Tom's talk was proved "cheap" when he left blink-182. The second interpretation could be that Mark listened to Tom talk about his band Angels & Airwaves when Tom said it was going to change the music industry and be the greatest rock band in the world.
"And my mouth is filled with blood, From trying not to speak" - this line is, obviously, about Mark keeping his mouth shut and not going off to the press like Tom did.

"So search for an excuse, And someone to believe you" - when blink-182 was in its final months, Tom kept making excuses for his behaviour and actions. Then, when blink ended, and people started to blame Tom for the break up, Tom started employing a variety of excuses (everything from "I'm 30 years old, I want to be more mature" to "They gave me an ultimatum over my family") and Mark became sick of it. He's saying Tom should just make up another excuse and someone to believe him.
"In foreign dressing rooms, I'm empty with the need to" - Mark and Tom are now in "foreign dressing rooms".

Bridge:

"I lay rotting where I fall, I'm dead from bad intentions" - Tom's intentions were greedy, as the next line implies.
"Suffocated and embalmed and now all our dreams are cashed in" - "our dreams" means their dreams about the future of blink-182. Tom wanted to make as much money off of it as he could.
"You swore you wouldn't lose, then lost your brain" - Tom promised Mark that he'd never turn into a sell-out, or that he'd never changed, but then he changed drastically.
"You make a sound that feels like pain" - though this is quite a clear lyric, I'm not entirely sure what it's referring to.

I'm sorry if my interpretation is a little off, or if you don't agree with it. I believe everyone has their own personal interpretation of songs and, as long as they're not completely ridiculous, they're all right. No matter what you think the lyrics mean, you cannot deny this is lyrically one of Mark's best.