You shouldn't really stay by yourself if you have anxiety. All though, it can help people get through situations, Its not the way to go. If you talk to someone you trust or someone who you can relate to, its easier to handle the problem. Being as there is a person who has been through your problem and knows what to do about it.
Relaxing is also a way to stop anxiety.
Based off google:
"By relieving the stress in your muscles, you can usually reduce your anxiety levels. To quickly relieve your muscle tension during moments of anxiety". Listening to music while you relax, is also a way to stop anxiety.
Being in nature, or even viewing scenes of nature, reduces anger, fear, and stress and increases pleasant feelings. Exposure to nature not only makes you feel better emotionally, it contributes to your physical wellbeing, reducing blood pressure, heart rate, muscle tension, and the production of stress hormones.
Thus, being by yourself as much as possible will not reduce/stop your anxiety. It will make it harder for you to calm down.