Can stress and anxiety increase your resting heart rate and cause it to fluctuate minute to minute? my usual resting heart rate was 55-65 a few weeks ago now its anywhere from 66 - 96. even when i am not anxious.

Yes it can: The numbers you have mentioned fall within normal range for a young otherwise healthy man If you keep checking the pulse and thinking about it this might make you anxious and heart rate will start go up.

HR fluctuation: HR does fluctuate moment to moment.If there has been a change would check thyroid function as that is associated with HR changes , check for caffeine, energy drinks and medications like claritin D / decongestants which contain phenylephrine/pseudoephrine and are associated with elevated HR and consider evaluation for POTS which is a rare cause of elevated HR f/u/ w/ doc

Yes; definitely!: Your mental state can affect your heart rate as well as medicines and foods that you are taking, such as energy drinks, which are really just caffeine. Also, physical activity as well as emotional upset (thinking about Trump!) and numerous medical conditions. If it persists see your doc.

Sympathommetic: Anxiety, dehydration, feat and caffeine are a few causes of increased heart rate all through the same mechanism -- mainly drive up heart rate in response to adrenergic stimuli.

Of course: This is normal. If you feel well otherwise, stop taking your pulse. Almost everything you read about "healthy pulse rate" is subscience / entertainment misrepresented as "health informaiton". You should be proud -- a resting heart rate around 60 suggests you're an athlete. Keep it up. I hope you can find a life situation where the stress is healthy and conditions are less anxiety-promoting.