Suicide isn't the easy way out, and it's definitely not the most selfish thing someone could do. The most selfish thing someone could do is to demand that another person, whom they supposedly love, should languish in constant emotional pain so that they don't have to experience loss for a brief period of time. That's selfish. It's asking the person to go to lengths for you which you're not willing to even approach for them. Certainly, you don't just "get over" something like that, but unless it actually makes you kill yourself, too, I don't think it's very fair to compare your pain to theirs.
The saddest thing I've ever heard was a story of, I believe it was a Dutch woman, whose daughter struggled with depression her entire life, most of which was peppered with stays in psychiatric care that failed to help her. She sought assisted suicide and, after being turned down, and after being released from protective care following that request, she overdosed herself. The woman said her daughter died alone, clutching a stuffed animal for company, instead of her mother's hand, because her only option to do it was in secrecy. It's infuriating that something like that should happen in a "civilized" society.