^d-dimer270 so ct scan was done- clear.lately having palp, low energy, fatigued, feeling like i'm not getting enough air in.thyroidectomy 5/31. cause?

Many possibilities: Your symptoms of palpitation, low energy though not specific can be associated with thyroid dysfunction. With your other medical issues, it would be wise to consult with your doctor sooner rather than later. If not recently checked, you may need to check a tsh, but also ekg to make certain that your heart rhythm is normal. As for not enough air, again nonspecific, but indicates need for a checkup.