04/26/2011 at 10:35 AM EDT
Before Lindsay Lohan
heads to an L.A.-area morgue for her community service
, the troubled starlet stopped by the Tonight Show
for a surprise chat with Jay Leno.
In an interview scheduled to air Tuesday night, Lohan, 24, clad in a silky black pantsuit, said her punishment felt "shocking" and revealed she feels "kind of numb."
"I'm not a kid anymore," she said. "I'm 24. I've made a lot of mistakes. I recognize that, but I'm in the clear now and I feel that as long as I stay focused, I will achieve what I want to achieve."
According to insiders, the starlet received a standing ovation from the audience when she came out.
Lohan also talked about resuscitating her film career, starting with a role in the upcoming Gotti: Three Generations
, in which she's scheduled to play Kim Gotti,
the wife of John Gotti Jr.