I have a lot of trouble breathing - was wondering if this could be a histamine reaction? What should I avoid?

Was typing a report (medical transcription) and noted that this person had histamine headaches - much like headaches I have had - plus my breathing doesn't every get really good. I eat a lot of pizza and tomato products - and will drink some occasional red wine. I am approximately 100 pounds overweight and would like to excercise, but cannot walk across the room without gasping for air - have no reason to believe it is cardiac related - am 58 y/o but never had problems with my heart - have had bouts with asthma - but not even sure if that is for real. Just wondering if anyone had any input on this.