So my landlord hasn't given me my security deposit back yet 2 months after the lease ended. He also didn't send me an itemized list of damages within 30 days (he sent it about a week ago after I asked him for it). He claims I did not send him my forwarding address until after 30 days, however I did send it earlier, I merely sent him a new one later since I had changed address since then and in case he lost the old one.

The main problem is that the paper trail of this is my landlord sent an email to my roommate asking for our forwarding addresses. My roommate sent back an email with the addresses. On August 1st (lease end date), my roommate sent a new email with an updated forwarding address for her. Unfortunately she doesn't still have her sent mails to him. I have my sent mail to her with my address, and she has a reply from the landlord with her 2nd email (and the 2nd email refers to the first with text saying "if you already sent the check to the address I sent before, that's fine too." I know that's not great evidence, but it's all I have right now, do I have a case if I have to take it to small claims court?

Yes, you have an excellent case. File.