3 Days to Go, and IPC Sections Still Got Me in a Tizzy

Mera dimaag toh khoon se bhara hai. I've been studying for this exam for months, but still, this one thing is bugging me - the distinction between 'attempt to' and 'intention to' in IPC 307, 308, and 309. Kya hai koi difference? They all seem to boil down to the same thing - intention to cause harm or death. But what if the accused thinks they're doing a good deed and is actually trying to save someone? Is it an attempt or not? Kahan dekha hai jo aik clear-cut answer diya hai? Main to hoon confused.

I've read all the notes, studied all the cases, but still, I'm not getting it. I've been trying to visualize scenarios, but my brain is not cooperating.