ONE WORD.
FAST.
I can't believe you had an injury ! That's awful ...and good for you grooming yourself. I do to and have for the past year.
IF you have long hair and want the 'beard' to lay flatter or straighter - I think thinning shears WILL work. My girls just had a groomer appt for the first time in a year and that's what they used on Chanel who has very long hair.
I've also used a dematting comb (it looks like a little rake) and drag it thru that long hair - it pulls out volume without cutting the actual hair and causing that choppy look like when we TRY to trim ourselves...