Weak, tired, slow heart rate, anxiety feeling but not anxious. Is this anxiety?

I have experienced those symptoms and it took me 2 years to find out that I had Hyperventillation Syndrome and could improve my symptoms/attacks greatly with proper breathing techniques. It's important to breathe in and out of your diaphram instead of your chest. Each day and each night I spend 5 minutes practicing breathing in through my nose for 4 seconds, out through my mouth for 5 seconds and then hold my breath for 2 seconds and repeat whole process again. I also use this technique anytime I feel an attack coming on and it helps. People who have HVS also often suffer from anxiety too as is the case with me. Hopefully this info can be useful to someone.