Hi ditzydanni87. Welcome to the forum.

I am not a doctor and I have no medical qualifications.

At present, the NHS lists the following symptoms as (possibly) indicative of Covid: a high temperature; a new (or worsening) continuous cough; a change or loss in the sense of smell and/or taste.  If you have any one of these then the NHS advice is to get tested. 

Although a sore throat was initially listed as a symptom of Covid, it's no longer on the list.  I think this might be because there are many minor viruses which cause a sore throat, and many people who've had Covid without the sore throat.

Taking your temperature daily is a wise precaution (I take mine every few days) and I think that as long as your temperature is normal and you don't have a cough and your smell/taste hasn't changed and you follow the usual social distancing rules and you wear a mask, then you should be ok to go out with a clear conscience.  

However, maybe you shouldn't visit your sick nephew until your throat is better. 

Meanwhile, carry on with the Chloraseptic spray and maybe steam inhalations to help clear the sinuses.  I suggest you buy a cheap facial sauna and use distilled/de-ionised water which most garages sell.