Not to worry. One of the hallmarks of personal injury law is that the injury victim does not get billed an hourly rate. Rather, the legal fee is a percentage of the gross amount recovered for the client.
Nearly all Massachusetts personal injury lawyers – as well as personal injury lawyers in other states - take slip and fall cases on a contingency fee basis. What that means is that your attorney will take 33 1/3% (or possibly more if your case goes into suit) of any settlement or judgment amount as his/her legal fee at the conclusion of the case. If your attorney advances any costs in prosecuting your claim, it is you that is ultimately responsible for any such costs.
With contingency fee cases, your attorney is required by the Massachusetts Rules of Professional Conduct to provide you with a copy of the signed, contingency fee agreement. This is the agreement that formalizes the attorney/client relationship. If your attorney does not provide you with a copy of the fee agreement, ask him/her for a copy of same.