Hayden Panettiere's Mom Says She Went 'Numb' After Hearing Her Daughter Was Dead

Hayden Panettiere's mom says she went completely numb after learning the tragic news of her daughter's death -- and she still has a hard time believing Hayden's really gone.

Lesley Vogel sat down with ABC News reporter Rhiannon Ally for an interview that aired today on 'Good Morning America' ... and she recalled the moment she found out Hayden died of a suspected overdose in Greenville, South Carolina.

Lesley said ... "I was just numb. I just couldn't feel anything. I still am not grasping this is real. It just doesn't, it doesn't feel real. My mind tells me it's not, at times. You know, it's going to be a process."

Hayden's mom wants her remembered as a talented, beautiful, outgoing and intelligent woman.

Lesley fired back at criticism from Gayle King and Megyn Kelly after they slammed her for zeroing in on Hayden's many life struggles right after her death.

Her response ... "I would say to the haters out there, you don't have a right to tell me how I mourn the loss of my second child."

But things weren't always good between Hayden and her mom. In a May interview, Hayden said she had a "tough" relationship with her mom over the years ... she left the door open to try to make things better, but it never happened. In response, Lesley told Page Six that she decided not to contact her daughter while following professional advice.   

As we told you ... Hayden was found unresponsive by her boyfriend Brian Hickerson's brother, Zach, earlier this month inside an Airbnb. Zach said he called 911 while Brian administered Narcan, but nothing could save her, and she was pronounced dead at the scene.

The federal Drug Enforcement Administration has joined the probe into Hayden's death ... along with the Greenville PD and the coroner's office.