Doing what on your own? Applying for a green card? If it’s a straightforward case - and yours is, because a denial of nonimmigrant visa due to immigrant intent is not a problem for an immigrant visa case - there is usually no need to retain a lawyer. Again, it is your mother who needs to apply for you, you cannot apply yourself.
By the way, you may want to keep the long shot option of DV lottery while you are waiting for the petition to process. Entries open once a year around Oct-Nov and if you get selected it is easier and cheaper as well as faster than a family sponsored visa. https://dvlottery.state.gov/
A fairly straightforward case like yours doesn't require a lawyer, but if you have the money and/or are unwilling to do it on your own, you could get a lawyer. Remember, your mother in the US has to initiate the i130 petition, and once that is approved by USCIS after several months processing, you wait the 7ish years before the next set of steps. And as Susie noted above, DV lottery is an option in the meantime.