Both suck, pretty pointless competition at that point. They've both lost out on what we'd consider a normal life. Obviously Trunks got to meet friends in another dimension, but had to leave them, although it seems like he's ok with it and is quite content being able to help with rebuilding his world. If he's happier I'd say his life is better.
I do think Guts being betrayed is worse, because I think that would hurt anyone and is likely to mess with their future relationships - though, he makes friends again later. Nobody betrayed Trunks, except Vegeta being a deadbeat, but they weren't close as Guts and his dad, Guts and his tribe (post-Gambino) or Guts and Griffith.
Born to a corpse, who cares. It doesn't matter in itself. It only matters if people told him about it and it made him feel a certain way.
Something about Guts is he's from a different world. Some of the shit might not even bother him, just like it doesn't bother Guts or Vegeta to murder, but it would bother Goku or Krillin. He's known friends to some extent, but he's never known peace. If he never expected some things, he might not feel bothered by it. He doesn't feel like he's missing out...why are people depressed nowadays? Sometimes because they're told they need X or need to meet Y standard, most of which are culture-bound and not actually part of our universal human needs (defining "universal needs" is contentious though, across places and times)..however, these "you need X" - the X is culture-bound, but the underlying psychology of it causing distress or depression isn't culture-bound - it could be something like psychological kinship, acceptance, safety (could be underlying feelings of: don't have X, get socially rejected, therefore won't be safe. If you ask "why?" you can get to the real root desire - LSD can help, so I've heard) or something else, which is common to basically 100% of human cultures - if not literally 100%. Hard to cognitively empathise with Guts, because his mind and personal values are probably quite different. Like he might not care about losing his arm. We do see that some things bother him though. With Trunks we barely get to see anything of his thoughts - is it because they just aren't shown, or is it because they aren't there?
Something about both of them is how they are after their enemy is defeated. Trunks finally beats the androids, and then what? He's been obsessing over that his entire life, so how does he handle life after his enemy is defeated (Super might show this)? Same for Guts, how does he handle life after Griffith's defeat?