'This could have really frightening consequences, because I can't cough I rely totally on the suction machine to clear secretions loosened by being on the ventilator'
Do you have a tracheostomy? I didn't think you did, apologies if I'm mistaken. If not a suction machine isn't necessary.
If there isn't clinical need for a trachy and you can get secretions as far as your mouth then you don't need to be dependent on suction you should be able to spit secretions out. What do you do with the suction catheter, actually stick it down your trachea orally??