So far all tests and blood work ups do not show anything that explains frequent body aches/flu symptoms, should i give up on an answer?

2nd or 3rd opinion: No - I think it is important to try and get to the bottom of your symptoms - that would be the best way to figure out a plan to get better. Sometimes you need a 'team' of doctors and I wonder if you've seen an ID specialist? Different doctors think in different ways, and I think you need a specialist or 2 to help out. Hope your primary doc can get the ball rolling here...