mucus build up in my throat for years?

Hi, welcome to the ehealth forum and I am glad to help you.
You seem to be concerned by the feeling of excessive mucus in the throat.
You might be suffering from post nasal drip symptoms. Post-nasal drip (PND) occurs when excessive mucus is produced by the sinuses. The excess mucus accumulates in the throat or back of the nose. It can be caused by rhinitis (allergic or non-allergic), sinusitis (acute or chronic), laryngopharyngeal acid reflux (with or without heartburn), or by a disorder of swallowing (such as an esophageal motility disorder). It is frequently caused by allergies, which may be seasonal or persistent through the year, depending on the allergen(s) involved. Mucus feeling in the back of the throat, congestion in the nasal and sinus passages, snorting to clear mucus from the sinuses that cannot otherwise be cleared by blowing one's nose and vomiting due to excessive mucus in stomach are the common complaints of the patient who suffers from the post nasal drip. Treatment may include antibiotics, nasal irrigation, acid control medication, allergy medication, and/or minor surgery. Allergy medications include antihistamines, decongestants, nasal steroids, nasal crolom, or combinations of these. Reduced contact with allergens is important when possible. Allergy injections may be used for long term relief when allergy is the cause.
You must consult your doctor for the definitive diagnosis and treatment as the same cannot be made online.
Hope this helps. Take care.
Note: This post is not to emphasise final diagnosis as the same cannot be made online and is aimed just to provide medical information and no treatment suggested above be taken without face to face consultation with health care professional.