3コマ目の「She said I was the one who wanted a house and I was the one who wanted a baby - and now I had it all. ..She said I had won.」は「彼女が言うに、家が欲しいって言ったのも、子供が欲しいって言ったのも僕で、今は両方手に入ってる。だから僕の勝ちだって・・。」程度の意。
4コマ目の「But, I feel like such a loser.」は「でも、完全に負け犬の気分だよ。」という感じ。
daughter (娘) something to give away (あげちゃうもの・オマケ) feel like (~のような気がする)
such a loser (とんだヘタレ・負け犬)
A:I feel like such a loser. Nothing is going well. B:Come on, lighten up. Everyone has bad days. Just don't give it up.