• I want to know what illness this is and what to do about it?

General info:
-I’m genetically an allergic person (I’m prone to allergies). This passed on me from my father.
-I don’t have any serious health conditions (that I’m aware of).
-I’ve been vaccinated two doses of Biontech.
-I catch a cold/flu (generally) several times during seasonal transitions.

I got sick one weekend. The symptoms included:
-sneezing a lot
-an itchy throat (coughing)
-a runny and stuffy nose
-severe headache
-moderate fatigue
-slight bleeding inside the nose

One day after these symptoms started showing I went to a private hospital otolaryngologist. He diagnosed me with allergic rhinitis and suggested that I use allergy medicine(montelukast) with the prescription he gave me. So I started using it.

After about six days all of the symptoms written above, except the coughing, almost completely vanished away.

It was about the time a normal seasonal cold, flu, or allergy would go away (they usually last about 4-7 days). But it didn’t make sense to me how the coughing didn’t go away along with them and stayed. This was quite unusual.

On the seventh day of the illness, we decided that I take a covid test. I didn’t take it any sooner though because the symptoms included sneezing which isn’t a covid symptom and the doctor told us that there was absolutely no need for it.
The result was negative.

Because the coughing won’t go away, my mother tried different and constant treatments such as:
-Putting an air-purifying machine in my room that releases lavender flavored steam.
-Applying a Vicks cream on my chest.
-Making lots of different herbal teas.
-Continuing to give me the allergy medicine.
-Giving me vitamin supplements.

None of them affected the coughing and it continued.

On the eleventh day, my chest started hurting in class. The upper part felt the way it feels when you apply mild pressure to a bruise (I mean it wasn’t a burning or a stinging sensation). The lower part kind of felt like the sharp parts of the bones was stinging my meat once in a while. My heart felt like it was slightly hurting and was uncomfortable too. But it wasn’t an unbearable kind of pain. It was similar to the caffeine-caused palpitation I went through a couple of weeks ago. It also made me kind of dizzy. And I don’t know if it has anything to do with this but I also had a derealization sensation at the same time. It doesn’t usually happen this strongly though, it made me feel like I was going to faint.

I was told that it’s normal for your chest to hurt when you cough too much. I believe they were talking about the irritation that you cause when you cough too hard. But the reason for mine couldn’t have been that.

It eased soon but my chest continued to feel uncomfortable.

On the twelfth day I went to a pediatrician working in another private hospital. He told me that he thinks the probability of it being covid is higher than the probability of it being allergic rhinitis. He suspected that I had covid before but it was gone at the time. Because apperantly people who catch covid-19 continue to cough for a while after it’s gone. He said it might also be some kind of allergic asthma that leads to coughing.

I wanted to know what you think of this.
What do you think it’s more likely to be?
What do you think I should do about this?
Should I get a chest x-ray done?
Should I take a second covid test?
Do you have any advice?