Direct translation, but a bit blunt:
* Je t'aime mais je ne te supporte pas. (This is very direct and might be perceived as harsh.)
More nuanced options, focusing on the positive:
* Je t'aime, mais parfois tu me rends folle/fou. (This emphasizes the positive "love" and acknowledges the difficulty.)
* Je t'aime, mais j'ai du mal à supporter [specific thing]. (You can replace "[specific thing]" with the action or behaviour you can't stand. This is more specific and less accusatory.)
Focusing on the negative (with a hint of irony):
* Je t'aime, mais je te trouve insupportable. (This uses irony to convey the love and the dislike.)
A more poetic option:
* Je t'aime, mais tu me mets à l'épreuve. (This translates as "I love you, but you put me to the test". This conveys the challenges the relationship presents.)
Ultimately, the best translation will depend on the specific context and your intended meaning.