Fully aware this might not be relevant to the OP, but I have a friend who had issues with random/rogue heart beats and varying pulse/bp that came on suddenly at the age of 40. Dismissed for years as 'panic attacks' or 'you're imagining it'.
Only now, several years later, and luckily with the support of a friend of a friend who is a consultant in the field, has my friend been diagnosed with a problem with the vagus nerve. Hardly anyone has heard of the vagus nerve - the cardiac specialist my friend was seeing certainly hadn't; it isn't a 'cardiac' problem', and yet it can cause drastic problems with the heart/pulse/beats/bp etc. And it often only manifests after the age of 40.
But it's very rare - my friend is now aware of exactly how rare - so it is probably not the OP's problem. However, my friend experienced the same dismissive attitudes for years - she was dismissed as 'making it up', 'imagining it', 'having panic attacks' and more. The fact that my friend is also profoundly deaf with other associated physical issues also clouded everyone's judgement - basically it was too easy to write them off as 'making a fuss about nothing' (I went to many of the appointments because I have some BSL experience) until at last someone listened and now a very specialised consultant has taken over my friend's case.
Obviously that is a rare condition, and highly unlikely to be the reason why the OP is experiencing her odd symptoms. But it does go to show that sometimes things are underlying that are missed because people see the obvious, rather than delving deeper, and no one is more of an expert on how they feel than the person themselves.
On the other hand, if the OP has been advised to try antidepressants (I'm not aware of the OP's previous posting history, but obviously others here are) and hasn't yet done so, and/or given them several weeks to work, then obviously she should follow the advice she already has, and then go from there if there is no improvement.
Best of luck.