If you re-mapped the keys, set them back to default and see if it works. But, it sounds like you have run out of filters for your gasmask. If you are out of filters, a medkit won't help you. You're gonna die.
check your input device like keyboard or controller i never came through any glitch in any game i have played in my life. there must be some technical issue on your side. check everything. ________________________________________________________________________ Metro Last Light | Metro Last Light Glitch | Metro Last Light Problem