Hi, sorry that happens. I've had a racing heart as well. I would guess, and of course don't know, that your waking up anxious rather than having a coronary event causing anxiety. Health anxiety is real and hard to deal with. I have some myself. I'd obviously get an all clear from your doctor regarding your cardiac health. You could always be evaluated more in depth through a cardiologist. This way you rule out the scary possibility that your heart really is having issues. Once you know it is not, you can then earnestly work on your anxiety. they prescribed buspar at night for sleep? So antidepressants can work on anxiety which improves sleep and I am guessing that is what they are trying to do with buspar. You want to make sure it is not activating for you though. Not all people are the same in terms of how they react to medication. Sometimes if Buspar is causing insomnia or activating to a person, they will play around with dosing to help. So, I'd talk to the doctor who prescribed the medication. I'd also work with a good psychologist (some good and some are bad, get recommendations) and work on coping strategies for anxiety.
Take deep calming breaths. Hang in there.
From what I know, BuSpar isn't very effective as a stand-alone drug, but it does affect serotonin. Drugs that affect serotonin can cause those temperature problems, so it could be the drug, or it could be the anxiety. I have those problems as well, it started when I took Lexapro and then a similar drug, Celexa. They gave me the sweats. I'm not on antidepressants currently, as they don't seem to work anymore due to some problems I had with one of them, but I've noticed that some of the side effects that started with taking them are apparently now mine forever. One of them is those temperature changes. But I'm guessing that would go away if the stuff the drugs messed up ever went back to working normally. It could also be anxiety. It's hard to tell, because medication often causes the same side effects you get from just having the disorder you're taking the medication for. As if thing weren't hard enough! What you have to do with the problem is try to solve it with therapy if you can so you can stop using drugs, and if you can't, balance the benefits you're getting against the downsides. I hope you find what works for you.