「I'm glad to see you are as well as you were 3 years ago」
「I'm glad you you are doing well. You haven't changed in three years!」
「I'm glad to see you are as well as you were 3 years ago」
「I'm glad you you are doing well. You haven't changed in three years!」
一番目の英語が一番近い翻訳だと思います。「安心しました」という日本語はよく「relieved」という英語に翻訳されますが、「relieved」は「ほっとした」というニュアンスがありますのでこの文脈で「glad」の方が自然な英語です。
I was relieved that he was the just as healthy as he was 3 years ago.
「3年前と変わらず元気そうで安心しました。」= I was relieved that he was the just as healthy as he was 3 years ago.
「（私は）（彼が）３年前と変わらず元気そうで安心しました。」の主語（私）と目的語（彼）を入れるともっとわかりやすくなります。
ご参考までに
イギリス 
アメリカ合衆国 
