Can COVID-19 in your body come back after it's gone?

When you say CRP test, were you specifically tested for Covid-19 and found positive? Or was it for C-Reactive Protein, which means that at this point, the only way to know if you had Covid-19 is with an anti-body test. I would be hesitant to run right out and get one, however, because many have players been allowed to come to market with NO independent testing or validation. If your doctor believes you probably had Covid-19, you should ask for referral to be tested by Mayo, or a major university or medical center near you, using a carefully tested and reviewed version.
As to your question regarding Covid-19, or any other virus, being able to "reactivate" itself, sometimes yes, sometimes no, depending on the virus. Right now, it appears based on very limited preliminary information, that the Covid-19 virus confers immunity for some unknown period of time, but that certainly will be studied further. That is one of the critical questions facing experts as they try to determine when and how to relax precautions.
What is known, and possibly more likely, is that it is possible to be infected by two or more viruses at the same time, or one after another. Sort of like getting the influenza followed by a cold.... here is a recent podcast that addresses that issue https://newsnetwork.mayoclinic.org/discussion/covid-19-mayo-clinic-expert-on-what-its-going-to-take-to-reopen-the-us/
Finally, the anxiety you are feeling now is very common - we are in an unprecedented situation, with rapidly changing conditions and even the experts don't have all the answers. Here are some ways to stay calm, and also to improve your sleep:
Limit your time watching/listening to news coverage and social media regarding Covid-19 to a very short time each day, and definitely not into the late evening. Pick one or two reliable sources like https://newsnetwork.mayoclinic.org/category/covid-19/ and maybe one newscast
Make contact with other people - friends, family or coworkers, and discuss anything not related to the current situation. Many people are using Zoom or Facetime to stay in touch visually - it has bee a blessing to me while I am separated from my children and grandchildren.
Occupy your time with activities you enjoy, such as reading, doing puzzles or games, or a hobby
Try to spend some time outdoors each day, practicing safe social distancing, and consider wearing a mask if you will be in public areas like stairways.
Get some exercise each day - preferably more than once if you can. This can be as simple as a short walk.
Make sure you are eating a healthy diet, and limit or eliminate caffeine, soda and alcohol consumption. If you have always relied on takeout or processed foods, use your time to learn to prepare some simple healthy meals.
As I like to close my posts, stay calm, stay safe & stay healthy
Sue

It was indeed a C-Reactive Protein test. The doctor said my value was very low which indicates no infection at all. This was 2 days ago.

The doctor said the same thing that the only way to find out if I've had Covid-19 is with an antibody test.

Two questions: 4/5 was diagnosed w/C19 and now in my final day of quarantine. My resting Temp is 96.9 went to 97.3 today and it never went above 98.7 during my Q ( tracking temp 2xs daily). Would you consider that a fever? And am I susceptible to getting or carrying C 19 to myself or others. Thank you in advance for your help.

@beachhouse Welcome to Connect. We are a group of people dealing with a wide variety of health issues, but we are not medical professionals, just folks wanting to share our journey with others like us.
Like everyone else in the world, we are learning more about Covid-19 every day, but I'm not sure that even the experts have the final answer to your question yet. That said, I know my daughter's symptoms came and went for over 20 days, and her provider told her to stay home until she had been symptom free for 72 hours. There are also reports of people with apparent "relapses" after they thought they were completely recovered. I don't know if they were tested to determine whether the virus was still present.
When you say you were diagnosed, was it based on a test or your symptoms? In most cases, a temperature of 98.7 is not considered a fever, but not everyone has a fever with the virus. Do you have other symptoms? Have you called your provider for advice?
Sue