1) What does "spaced" mean in "Dude, you know you have been really spaced lately"? I can only assume as Rhiannon did that it is short for 'spaced out'. 2) What does "drop the sack" mean in "I dropped the sack and straightened up"? It is probably literal. He was carrying a sack and put it down. 3) What does "bottom out" mean in "my heart bottomed out"? 'Bottomed out' means arrived at the lowest point. I assume it means the speaker became as sad/depressed/lovesick as they have ever been. 4) What does "tackle" mean in "he tackled me with a hug"? He came up at speed and hugged me vigorously. The hug was almost like a tackle in rugby or american football. 5) What does "spitty burst" mean in "he cried in spitty bursts"? I see it as crying out loud - something like 'blubbering'. Spit was occasionally coming out his mouth as he was crying. In all of these, more context helps. With such a small amount of context, it can be hard to know what is meant.

Dude, like really, man? You ask 5 preguntas, hombre? Don't be a slacker. Look it up yourself. C'mon dude.

Most of these are slang to which I recommend Urban Dictionary. Slang is not my forte, but I will give you the best answers I can. In the first one the speaker is using a shortened version of "spaced out" which basically means whoever he's talking to keeps zoning out (staring into space while thinking). The second one is either a metaphor or he literally means he dropped a heavy sack so he could straighten his back out. I am very unsure of the third one but it seems to be akin to "gave in". The fourth is not slang. Tackling is an attack where someone hits you with all their weight in order to knock you over, so in this case he's exaggerating the intensity at which someone hugged him. The fifth isn't slang either. In this case the author of whichever literature you found this in is attempting to give you a picture of how this person was crying. I can't really visualize tears as spitty so I'm assuming they were spitting all over their face while crying, but then in that crying it was stopping and starting rather than being constant.