You can get your felony expunged, since you did not go to prison. However, even if it is expunged, it's still a strike if you're convicted of a subsequent felony.
You can get the court not to count the strike in a subsequent case, but the procedure isn't an expungement. You have to have your lawyer make what they call a Romero motion. And the judge decides this on a case-by-case basis.
You can apply for an expungment under Penal Code 1203, etc., but the strike will always stay on your record. It doesn't get wiped from your record, just saves you from disclosure in the future, with exceptions.
There is one procedure which could possibly help you, but it is both expensive and time consuming. First of all, I need a lot more facts. Did you use any weapon? How badly was the guy injured? Does mom finally want to tell the truth about how you were defending her? What pressures were put on you to plead guilty, other than what was mentioned?
The reason I ask these questions is that if not too much time has passed since you were convicted, it is possible to bring a petition to vacate the conviction and re-instate the charges. You'd have to prove both that you were unfairly coerced into that plea and that you have an excuse for not bringing the motion sooner. Then, if the court grants the petition to vacate, you have to either go to trial and get an acquittal or dismissal.
THEN, you could petition the court for a factual innocence finding. If granted, you get your arrest record, your plea, and conviction sealed for three years and then all such records physically destroyed and police computers purged of any mention of the case.
Two down sides to trying this: One, it is a three step process and takes a lot of time and money (Maybe around $20K) to do, with no guarantee of success. Two: you could be found guilty after a trial and then sentenced to prison. However, under your circumstances if your mom testifies in your behalf, it does not seem likely a judge would do that. But the risk is there.
I see no other way to clear your record.