COSTA MESA (CBSLA) – The Costa Mesa community is rallying around a teenager who has a serious illness that has left him paralyzed.

One thing Jacob Fesili loves to do is play the trombone. The 8th grader is so skilled that he was moved up to the high school band.

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But during a competition last month, Jacob was feverish and thought he had the stomach flu. It turns out it was much worse: an autoimmune disease known as Guillain-Barré.

Within a few days, the 13 year old was paralyzed and on a ventilator.

It has been six weeks and Jacob still can’t walk, but he’s getting better at a rehabilitation center.

The Costa Mesa Police Association adopted his family for Christmas knowing they need a lot of help and support.

“Thank you for rooting for me, and I appreciate it a lot,” Jacob said.

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Both Jacob’s mother and father are using vacation and sick days at their jobs so they can be by their son’s side, as well as care for their other two kids – and those days are running out.

“I’ve known this family for many years, they’re always the family that’s there to volunteer for a booster group or to come out and help with the band or the community clean ups,” Costa Mesa Mayor Katrina Foley said. “They’re always there for us. It’s our turn to be there for them.”

To get through every day, Jacob keeps repeating the same mantra: “I can do hard hard things.”

He has had moments of doubt, but the teenager knows he has a whole city behind him.

“Remember that it’s gonna be over soon, and just push through it so that you can enjoy everything,” Jacob said.

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A GoFundMe has been established to help pay for Jacob’s medical bills.