What Causes Shortness Of Breath And Congestion In Throat On Smoking Marijuana?

i smoke weed consistantly but i smoke a strong dose of marijuana one night and i felt like i could not breath and i had an irregular heart beat and ever since then every morning and night my symptoms are the worst i feel like i can breath sometimes it feels like my throat is closing up and i always feel like i am shortness of breath , i went to the doctors and they said i had a mucase problem but i no longer have a mucase problem but i still feel the same what can i do to releave this?