Terminating rental agreement due to mould and problems in the apartment
I have a rent contract of 3 years and now I'm halfway (1 and half year left of contract). I want to terminate my contract because this apartment has water leaks, humidity and even mould. The first time I've tried contacting and informing my landlord of the water leak was already in 10/2020. Meaning I had just moved in a month ago and the problems started already. Landlord sent handymen to come fix it up only in spring 2021 when the water came through the roof. Fortunately that is now fixed BUT these same problems still continues only on the other side of the apartment. It's visible to see the wet spots and mould. Now I have been getting severe allergies due to this mould and humidity in apartment. Such as, short breath, nose bleeds and rash.
My question is, is it illegal in Belgium to keep renting out apartment that is not liveable, and can I terminate the contract without needing to pay penalties or losing my deposit since non of these were caused by me but due to the bad conditions of the apartment?