Headache, Dizziness, Tiredness, Jumpy Legs, Nausea, Have Cold. Had Diarrhea. Help

Hi, for the past 6 months I have felt generally unwell. Over the past couple of months I have felt achey like flu quite a lot of the time. I have had headaches and dizziness, random sleeping, waking in the night for a few hours. I also feel very lethargic, not tired but lethargic like everything feels like an effort.
Sometimes at night I have jumpy legs.
I have also had my fair share of diorreah and sickness bugs this winter.
I also feel nauseous most of the time.
I caught a cold a week and a half ago and it has hit me like a ton of bricks, I really have struggled to get on with things, taking a two hour nap n the day and going to sleep at 6.
Everyone else around me has caught the cold saying it was a bad one but it only lasted a couple of days in them. However, it still seems as bad as ever in me.
I constantly feel like I have flu.
I feel like something is wrong, I'm not quite right.
Can you help me? Thank you