I used to think it was great to live overseas, then I realized it's not everything it's cracked up to be.
I was always envious of people who could live overseas, but there are difficulties attached to that life as well.
この場合、次のような言い方ができると思います。
ーI used to think it was great to live overseas, then I realized it's not everything it's cracked up to be.
「以前は海外生活って素敵だなと思っていたが、言われているほど良いものではないと気がついた」
to live overseas で「海外で暮らす」
not everything it's cracked up to be で「言われるほどではない・期待したほどではない」
ーI was always envious of people who could live overseas, but there are difficulties attached to that life as well.
「海外に住める人たちがいつも羨ましかったが、その生活には困難も付いてくる」
I was always envious of people who ... で「私は…な人たちがいつも羨ましかった」
there are difficulties attached to ... で「…には困難が付いてくる」
ご参考まで！
I was envious of life abroad, but I had the wrong idea.
"海外生活がうらやましかったけど、思い違いだった"
- I was envious of life abroad, but I had the wrong idea.
- I used to envy life overseas, but I was mistaken.
夫の海外出張についていく奥さんの海外生活がうらやましいなあと思っていたけど、実は大変なことが多いとわかった。私の思い違いだった。
- I used to envy the lives of wives who followed their husbands on business trips overseas, but it turns out that it is actually a lot of work. I had the wrong idea.
カナダ 
アメリカ合衆国 
