Hi, I'm a 24 female, had RML of lung removed last year due to cancer. No chemo needed. Recovered well, but since then I'll sweat and get light headed but not winded with light work. Sometimes I feel great and full of energy, but these past few months, often I feel like I'm 60 years old and light work makes me sweat and lightheaded, sometimes followed by sharp pain in my side. Should I get this checked out?