What you describe with hot flashes and light-headedness and tingling and not being able to move sounds like a panic attack. I had a really bad one awhile ago and thought it might have something to do with my heart. Apparently this is a very common occurrence where people who have panic attacks think they are having or have had a heart attack.

I also felt my heart was having issues and I believe due to lack of sleep I had panic attacks. But the doctor also told me I was fine with an EKG and drawing of blood. They said it was likely due to stress and lack of sleep. They gave me medicine to take but I didn't take it due to the horror stories I read about it. I've been going the natural route and exercising some more and started taking apple cider vinegar and vitamins and found some other helpful things so I will explain what I've learned.

Be sure to get some exercise, enough rest and proper vitamin supplements. For anxiety relief you can try some of the things on the link below like a bit of Apple cider vinegar each day seems to help, as long as you don't have ulcers, but maybe drinking with some water or something anyway: [link to www.earthclinic.com]

There are many other benefits from adjusting your bodies pH level like that as well. It should be slightly alkaline, like 7.4. Your cells can't function well or at all if the pH is far too high or too low.

Another thing you could try is Oil Pulling which has all sorts of other benefits as well. You can look it up at that link too.

You can also put some lavender scent or other scents in the room to help calm you. We got an oil diffuser that used ultrasonic sound frequencies to evaporate the water which was nifty. I think it's like water ionization or something, although that can be a different thing.

Speaking of which, make sure your water is healthy too. But be careful of alkaline water ionizers as they aren't necessarily doing what they claim: [link to cleanairpurewater.com]

Also passion flower works really great but you can't take it too much or for too long or it can have negative effects on your body. If I felt myself starting to freak out a bit I would take some drops of a tincture in some water and it calmed me right down. I have some sleeping pills which have melatonin and passion flower in them which are awesome. Take those a couple hours before bed and you will sleep great.

Another thing that happens to people who have panic attacks can be that they start to panic about having a panic attack. So just try to breathe and relax and not worry about anything. I also sometimes find just turning on music, a movie or a show or something to take my mind off my thoughts helps fairly well.

Also magnesium is often a thing people are quite deficient in and having some of that can help you feel better as well. It also might help to offset any calcium build up you might have in your heart or arteries and so might the Apple cidar vinegar. [link to drsircus.com]
[link to www.earthclinic.com]

Another thing I discovered was that pomegranate can clean out your arteries over time. One study said it reduced the amount of plaque build up in the arteries by something like 30% in a year of drinking pomegranate juice regularly or taking supplements. Here are some various sites on that: [link to www.webmd.com]
[link to www.lifeextension.com]
[link to umm.edu]
[link to www.greenmedinfo.com]

For what it's worth, a friend of mine had the exact same thing described about a pain under the arm and the Doctor told him it was just a sore muscle, probably from being on the computer a lot. I sometimes get a sore muscle there but I know it's just a muscle because I used to work as a construction labourer I know what sore muscles feel like there so I just massage it a little and it feels better. But that isn't necessary the same thing you describe, just one potential cause of something similar you describe. I'm not trying to downplay the seriousness of heart issues.

If you spend a lot of time on the computer definitely take regular breaks from it. Sitting down all the time isn't good either. Maybe implementing a better system for taking breaks is in order which can also help increase productivity: [link to lifehacker.com]

Good luck and hope you feel better!