The simple spirometric measurements, such as forced vital capacity (FVC) and forced expiratory volume in the first second of exhalation (FEV1), are within normal limits. The lung volumes, such as total lung capacity (TLC) and residual volume (RV), are very much dependent upon age and height. From age 20 to age 60, the RV may increase by up to 50%, while the TLC remains almost the same. Thus the RV/TLC ratio also increases, above the upper limit of 35% at an early age. While an increase in RV/TLC may be one of the first signs of chronic obstructive pulmonary disease (COPD) and, as previously stated, an increase in the ratio may just be a function of age.
This is all "academic" as your spirometry confirms that you have excellent lung function with good pulmonary reserve. Your doctor is right to not "seem worried" and you have no reason to worry.
This sounds like the same problems that I have-you have all of these symptoms and all the doctors tell you everything is fine and it's only anxiety. That about right? I've been having probs with shortness of breath for close to 2 years now!! I am not willing to accept that it's only a psych prob. Hopefully, your doc believes you and is looking into some possibilities.