Fatigue this severe after two surgeries, general anaesthesia and three weeks of bed rest is often linked to deconditioning, where the body loses fitness and muscle strength from being inactive that long, especially after real physical trauma. Your normal
thyroid,
sugar and scans don't rule out anaemia or simple physical deconditioning as the cause.
Next Steps
Please see a general physician for a full checkup including haemoglobin and iron levels, and ask about a pulmonologist referral if breathlessness on exertion continues, since that needs its own look. A structured, physiotherapy-led reconditioning plan can also help rebuild your stamina gradually.
Health Tips
Go in sooner if the breathlessness happens even at rest, or you notice leg swelling or your lips turning bluish.