You left me in despair.
Very unnatural, especially the use of 置き去りにする. 置き去りにする means “leave someone alone and go away”. It implies that “both you and I had been in despair, but only you managed to escape and left me alone”. I don’t find such a context from the English sentence. My alternative translation is:
お前のせいで、俺は絶望の淵に沈んだ。（おまえのせいで、おれはぜつぼうのふちにしずんだ。）= (lit.) Because of you, I fell down to the pond of despair.
俺 is a masculine casual/wild version of 私. お前 for you matches with 俺.
Please be noted that many Japanese native speakers say 絶望の淵に立った(たった) instead of 沈んだ. But 淵 means the deep part of a pond/lake. You cannot “stand” on 淵. A professional proofreading team at Mainichi Newspaper (one of the big five national newspapers in Japan) explained the common mistake here.