I Work Out Regularly, But I Seem To Lose Gains

I work out regularly, but I seem to lose gains easy. I ride a bike a mile up hill most days and it doesnt get easier. Every 10days I become exhausted, my calves tire easy and have joint pain, sometime rest for 24hrs and feel good again, but it seems to progress over the last year. A bad day I feel nausea and weak. I eat fish chicken, v8 , fruit smoothies. varies 2 eggs and toast sometimes slice of bacon. lots of coffee cream.