Weakness and flu for year. Is an issue?

Hi, I am 31 male, height 5'11" and 68kilos. I smoke 10 per day and drink only beer once a week. No exercise and diet homemade mostly. I am getting phlegm from chest and nose, sometimes white, green, yellow or transparent with black dots. This stays for months and also feel weekends. For Last 7 months, feverish from 6pm onwards till late and normal during day time. For last 5 years, itchy rashes on my leg shin only. Don't understand on how they behave. Suddenly it itches for days and it stops for few days. Doctors in UK could not diagnose this. For last 3 years, slight pain in chest as if some needle is poked. I had this when I was child and it came back at age 27. Lung test: clear Blood test: clear Liver test: clear Stool test: clear Pancreas test: clear Ultraso... Test: clear Why suddenly so many things are happening? I don't even remember getting fever before age 27. Does all these symptoms of something or just lack of proper diet and exercise is an issue? Please advise.