Over a month-long nasal infection. Need help

Started coughing a lot an getting thick phlegm in my throat and nose at the beginning of february. Thought it would go away if i drank enough water an had enough rest & also tried self-medicating with whatever leftover pills i had from previous infections. (I get sick frequently due to my weak immune system, bad diet, lack of sleep, sensitive nose etc.) Finally visited doctor late feb & was given antibiotics and pills to unlog the phlegm & nasal passageways. After finishing the antibiotics course and the other medications i still have phlegm and mucus stuck everywhere; behind my throat, behind nose making me sound nasally at times and especially behind my ears. It has been so annoying and irritating to clear so much mucus everyday just to have it come back once i wake up the next day. I've tried everything from drinking more water, trying to unclog the nose in the steamy shower, using prescribe nasal spray, coughing up & blowing as much mucus as i can and it comes out yellow and thick until now. I am just frustrated and need quick recovery advice. Especially for my ears which feel so congested 24/7 even if i do the nose-pinch and blow method. Ever since my ears got clogged from a similar infection years ago, the mucus just feels like it has been stuck there from then until now and my hearing is slightly worse than it should be. Please help me out. I'll provide whatever information is needed, this is the only place i could think of to go for help because yet another doctor's visit seems ridiculous and costly. I basically visit the doctor every month.