Okay what is your scientific side telling you on this issue?
A few things based on the evidence we have so far:
1) On background, there are 7 coronaviruses known to infect humans. Four are amount the over 200 viruses known to cause the common cold. Together, those four cause about 12-20% of colds. We know that immunity to each of them lasts 1-3 years. The other three are SARS-CoV-1 (SARS 2003), MERS-CoV (MERS 2012), and SARS-CoV-2. SARS 2003 and MERS burned out so fast we can’t test immunity, so that’s currently unknown. But of those we know, it’s 1-3 years.
2) The genome for SARS-CoV-2 seems to be fairly stable. There have been no observed substantive mutations. Without mutations affecting the outer protein structure, there should be no issues with the immune system properly recognizing and responding to the pathogen in the future following an initial infection or inoculation with a vaccine.
3) The human immune system readily reacts to SARS-CoV-2, unlike some things like HIV. And SARS-CoV-2 doesn’t attack the immune system directly or cause direct damage to it. Measles, for example, can wipe out ~70% of your memory B-cells, which can erase previous immunity built up to various pathogens and leave you exposed again. SARS-CoV-2 doesn’t seem to do anything like that.
4) There have been no known cases of reinfection with SARS-CoV-2, which - given how widespread it is - we should have seen by now if zero immunity is conferred as a result of infection. There were some initial reports of reinfection, but those turned out to be positive PCR tests triggered by lingering viral proteins; NOT newly active infections.
Based on that available evidence and more, it would appear that we have at least a decent level of immunity after infection and that it lasts at least ~4-6 months. Beyond that is speculation at this point because we don’t have enough data.
But if you put a gun to my head and made me speculate, I would GUESS that based on the slow rate of mutation and observed immune response, we’re looking at a minimum 1-3 year immunity and possibly lifelong to this particular virus. However, SARS2003/MERS2012/COVID-19 tells me we may see a new variety in the next 6-12 years. If that happens, our level of immunity to it will depend on how crossreactive the antibodies are.