firstly welcome to WAB
secondly . . . . aaaargh! do be careful

for a start that looks like it's going to be a dark-spored species - have you prepared a spore-print? - if it has dark spores it isn't a
Marasmius; also you don't look to have all the stipe (stem) there - characters of the stipe-base can be important in diagnosis (of the
fungus that is, not the potential patient

)
from what one can see, your fungus looks rather like a
Psathyrella and the classic spring one is
Psathyrella spadiceogrisea which could well be what this is - but . . . . .
you will note that there is an embargo on "is my fungus edible?" posts on this site; I fully appreciate that this is
not what you have done here, but do be careful - there are
thousands of larger fungi out there, only a tiny proportion will be in a guide such as you describe
in the first instance, your best bet is to go out with people who know their stuff
cheers
Chris