Hi
First of all , post dengue infection and bed rest, it's common to have weakness and fatigue due to lowered platelet count and energy depletion.
But he consistent in your exercises. Always to start exercises follow the sequence
Warmup
Aerobic/anaerobic activity
Cool down
Also add some breathing exercises as routine.
Again healthy and nutritious diet intake makes a lot of difference. Follow these tips . You will definitely feel better.
Next Steps
For online consultation, you can contact me if you need guidance on this.
Health Tips
Look into the mirror and be conscious not to bend while walking and sitting.