How do i get to see a medical expert for an overall opinion on my secondary life threatening problems, do i need to go through my doctor first?

Usually no problem: Rules are usually caused by insurance companies or the government. Aside from that, one can see any doctor she wishes to see and pay for. If she is unsure of her conditions, she can see an internal medicine doctor for a second opinion. If she knows her conditions, she can see specialists who treat those disorders for second opinions. For example, for aches and joint problems, try a rheumatologist.