i have 2 8oz bottles of robitussin dm it has dxm and guaifenesin as the active ingredients ive done 1 8oz bottle of this stuff before and the guaifenesin didnt make me feel sick or nothin do you think if i did 2 of these 8oz bottles ill be fine? i wont OD will i? i will be taking about 9000mgs of guaifenesin that seems like alot about how much does it take to OD