You don't "have a case", you have a difficult landlord and the sooner you get out of an apartment with a mold infestation, the better.
Congratulations on making the decision to relocate. Moving is a pain but getting sick from mold is not worth it. Don't ever tell your landlord about maintenance issues - write to the landlord, and keep a copy of what you wrote.
If you can afford to, pay rent at both places so you can take your time moving. If you leave early "due to conditions" you run the risk of ruining your credit and here's why: because you haven't given notice of your maintenance issues in writing. Without independent evidence, it is impossible to demonstrate that you complied with the RLTA, and your old, nasty landlord will likely convince a judge that you are simply deadbeats complaining rather than paying rent. Your landlord is under no obligation to return rent that you have paid.
You can look up your landlord through JIS-Link to see if they have been involved in lawsuits before. This is public record.
I know this sounds harsh. But wouldn't you rather have a candid assessment than get into court and hear it from a Judge ordering you to pay your landlord even more money?