I don't think Worndown gave that reply because Wojaczek was not encouraging OP to die, but rather because of how the comment is worded out.
"your reasons for wanting to die sound like every teenagers reason for wanting to die (they are still valid enough reasons of course but still, nothing to kill yourself over imo)"
This comment may make it seem like the reasons teenagers want to CTB are different and less significant than the reasons adults have, I don't think adding "they are still valid enough reasons of course" would do any better when that same comment is also isolating the reasons younger people have to CTB and may make OP and other younger people reading this feel invalidated. I'm 18 years old, and I can say for myself that's how I felt about that comment.
How can you confidently say that one's struggles are "very beatable" when you're not in their position? Do you think you could be the judge for a life that is not yours?
For an example, we could use one thing that OP has mentioned, which is their girlfriend breaking up with them. The way that every person would feel after breaking up with a partner are different, we are all unique people, with brains that are wired differently. Just because you may find it easy to move on and recover after losing somebody you love, doesn't mean others would find it as easy as you may do. The importance and attachment that each person have for the ones they love, and the circumstances of a relationship, all differ too. For example, most people may find it easier to recover from losing a toxic relationship that has only lasted a few weeks, whereas it would be significantly harder for them to recover from losing a loving relationship that they were happy with that lasted for years.
When one gets to a point of having their life dedicated to loving and being with their partner, spending most of their time with them, and looking up to a future where they could build a new life and start a family, it's completely understandable that they would feel the want to CTB when they lose the relationship they had with their partner. I believe if that, or any other reason, is a valid and justified reason to CTB, should be completely up to the one who owns that life, not a different person with a different kind of life.