Sounds like anxiety but have you had a visit with your doctor just to get peace of mind? That would be a good first step.
a counselor can help you manage anxiety. It's hard to do on our own.
something really helps me are audio meditations on you tube for anxiety, depression, getting a good sleep,etc. just do a search, use earbuds, lay down and listen.
many to choose from. A couple that I like are called
detachment from overthinking,
train your mind and body to relax, sleep, relieve anxiety
clearing subconscious negativity
if you're having a full-blown panic attack, search for panic attack emergency
you need to get control over the anxiety. The worst thing you can do is react with anxiety when you get symptoms. This will increase your anxiety.
when your doctor tells you you are healthy, then you need to really work on managing the anxiety. When you get anxiety symptoms, don't try to fight them off. Acknowledge them in a calm way . You can even say " I know I can feel my neck sensation. It's ok." A book that would really help you is called Mindfulness. It teaches you all of this!
For shorteness of breath, slowly inhale through your nose making sure your belly rises.Exhale through your lips as though you are blowing out a candle. While you are doing this, think about how the air feels when you inhale and exhale. Do this several times. Whenever you are feeling anxious or have crazy thoughts, come back to the breathing . It brings you back to the present moment.
see your doctor , do the meditations, do breathing exercise and get the book! 😁