Help request for my Double Yellow Hibiscus

Hello everyone, I am opening this thread because I am humbling ask for your help since I am really desperate.

My melodrama, looks like start suddenly dying and I am fearing for the worst, to me looks like he caught the Hibiscus yellow mosaic virus, but I need your help to understand if it is the case or something else.

Bit of history: during the past summer he has suffered a thrips invasion that I fought spraying some neem oil, but after some months a Dhalia that has been gifted to me passed to him lots of aphids. Soon after he started yellowing some leaves, I thought it could be a matter of the fact that he has grown up really fast since the past March and lacked some fertilizer, I've just chosen some potassium-based fertilizer that hasn't made any difference after a month, so I just quit in order to not stress him too much.
I've always been careful to water him only when the soil was dried, I keep him indoors and in the room, the temperature is not that high also during the warmest days, so usually I am watering him 2 times a week during the hottest day, once a week when during the warm weather, and once every two weeks during the winter.

I've done some research and find that one of the causes that could be caused the leaves getting yellow might be Chlorosis due to the lack of magnesium or iron. Since from the picture I saw, at the beginning looked to me it could be caused by the lack of Magnesium I've just added a spoon of magnesium to the soil taken off a bit of old soil from the top of the vase (without touching his roots) and replaced it with some fresh soil.
One week has passed, where he was looking good and stopped making yellow leaves, but two days ago the situation just suddenly worsened a lot and the pictures I am gonna attach are the results of just two days.
Please help me, he is 6yo, and I am really attached to him. I know that if it is the case of the Hibiscus Yellow mosaic virus I have probably to get rid of him. So I am trying to figure out what is the real cause, and anyway trying to save him. So if anyone has some advice or suggestion on what I can do, I'll be glad to listen to it up

Thanks in advance to anyone who would like to answer and help me.

 

I am not much help I don't really grow house plants that if it is a house plant, I don't grow any of the hibiscus . I would say it does have a virus especially as you've mentioned aphids / thrips which are carriers , whether it mosaic virus I not sure but it does favour it . I'd remove the badly affected leaves to start with the are not going to recover .

 

Thank you very much for your reply and help, I'll follow your advice on the yellow leaves ....probably will lead me to understand what pattern the chlorosis of the leaves is following. Thanks <3