I have asthma and my chest feels very congested but i caint cough nothing up but my asthma is worse because of this would taking mucinex (guaifenesin) dm work?

Must treat Asthma: Mucinex (guaifenesin) does not do anything for asthma, which is a potentially life threatening illness. Asthmatic bronchitis has cough and needs attention by an experienced Doc., best is a pulmonary specialist. Generally they have completed an internal medicine residency and fellowship in pulmonary medicine. A family practitioner may also help at least to start.

Mucinex (guaifenesin) DM is: unlikely to help much. Are you using your prescribed inhalers? If not, you should start them. If you are and are still having difficulty, you should see your doctor so they can listen to your chest and also examine you for any other infection...so you can get the proper diagnoses and treatment.