Do I have MCAS?

Here is the list of symptoms that I am facing : Low blood pressure without any known cause for years. High heart rate(sometimes 150). I react to almost all foods but not with hives but with symptoms like dizziness,stomach pain, weakness. I feel stomach pain while eating. I only feel dizziness after eating but not movement (Dizziness goes away after few hours of eating nothing) I can't tolerate heat(feel sick in heat) Constipation Tiredness after eating food Joint pain after waking up in morning

Few tests I had and other stuff : I don't have anemia, hypothyroidism or hyperthyroidism. I have high IgE levels. I feel somewhat better after taking Bilastine 20 mg. Medicine doctors doesn't have an answer for my symptoms. Told me to cope with these to live.