Please bare with me this will be a long post it all started last September when I had chest pain for 3 days it didn't bother me cause I just thought it was muscle pain but my dad insisted I went to get it checked out anyway straight away they did an ecg and rushed me off to hospital saying something wasn't right all it was was that I had a fast heart rate so i was sent home then a few weeks later I was at work and began feeling lightheaded so was sent home had it for a few days went doctors they said stress it went away and then back to the start again with chest pain I then developed an obsession with my heart always checking my pulse checking my body for signs of anything doctors said anxiety but still had all the tests done on my heart all healthy the lightheaded was checked out with mri all normal but now it's getting everyday that I feel faint like all the time I've lost my appetite my legs and arms are weak my vision and hearing goes funny I just can't see how anxiety can cause this everyday all the time 
Hey I really get how you are feeling. Yes anxiety can cause not only those but so many other symptoms which you will get if you keep worrying. I also rushed to hospital twice thinking I have an heart attack rather it was my anxiety. Only you can convince yourself and get symptom free. Work, go out, have fun, start thinking about something else. Keep both your mind and your body busy and you'll feel better. Take care.
Kayleigh
Sounds like an anxiety, you have had all your tests and you need to understand you cannot have regular tests like those mentioned as some can be not only expensive also they may cause problems if done over and over again you need to control your fears
Have you tried Mindfulness or even Breathing Techniques, these may help
BOB