to be greg is suffering. You killed your soulmate literally with your love, your son is a constant reminder of her choice to perish at your hand to create something new, and everyone expects you to be a rock and the sensible one despite all the superpowers running around.
You've literally supported your child while living in a van and pay for everything (like the gems fucking have any money) while he lives apart from you and trains in something you can't fully understand.
He can fuse with someone he cares about, something you desperately wanted with his mother but could never have due to being a human... So you decide to go out by sacrificing yourself for him, jump in the way of something to protect him one last time. Go full piccolo.
He "pinks" you, and you are reborn with new and strange powers...
But now you'd doomed to live forever, or at least incredibly long life... having to live with the knowledge you still will never see your beloved again.
To be Greg is suffering, sweet suffering.