You're afraid of going stir crazy. You'll miss your friends. You love shopping. There's a million reasons why social distancing and quarantine is awful. Believe me, I sympathize. However, whether your local officials have issued a stay-at-home/shelter in place order or not, you should be staying at home. Here's why.
1. Limiting social contact will limit the spread of disease.
The healthcare system can only take care of so many individuals at one time. Through social distancing and other protective measures like handwashing, you can limit the amount of sick people who require the use of the healthcare system.
2. The domino effect of the disease is weakened by space.
By putting distance between yourself and others, you make it harder for the disease to "latch onto" other people.
3. Less exposure means less sick individuals.
Covid-19 has an incubation period of 2-14 days, and some individuals can be asymptomatic. So whether you feel fine or not, you could still infect hundreds of people.
The bottom line here is that social distancing/quarantine/lockdown/etc. is important. You are making a difference by taking such drastic preventative measures. Please continue to help the immunocompromised and the wellbeing of the hoi polloi by staying indoors unless absolutely necessary.