Yes, you should disassociate the domain from anything you are doing. You have already been notified by the trademark holder of My-Lemon and advised by YOUR attorney to remove it. Not to do so may (probably will) make you vulnerable to a lawsuit.

As a gesture of goodwill, I suggest you offer to transfer the domain to the trademark holder. It only has 10 months before it lapses. Besides, they can take it anyway. What are you out, $10?

Next, get with your attorney and register your new business name as a trademark so someone else doesn't come and take your new domain name.

__________________
DrTandem's San Diego Web Page Design, drtandem.com