GF gets twice as sick as me whenever I’m ill

Every time I get ill, infectious or not, my gf seems to get twice as sick the same day/the day after. If I have headaches she’ll get them worse. If I have a cough she’ll do constant little coughs whenever she thinks I’m in earshot. If I have aches she’ll have aches, etc.

I feel like I can’t just be sick without it being a competition. I’m rarely ill (handful of times a year at most) but it coincides perfectly every single time. I feel as though every time I’m sick and I try and do something fun to make myself feel better, she’ll be absolute misery guts and won’t let me recover in peace. If I’m sick I feel like she wants me to be miserable about it.

When she’s like this she just mopes around the flat and acts like my being ill is an inconvenience to her because she’s ‘ill too’. She has to one-up me on every symptom. I don’t expect her to do anything to look after me. I’m happy just sorting myself out when I’m sick, but she won’t let me do that without first making sure that I know *she’s* way more sick and miserable than me.

I don’t know why it happens and haven’t experienced it in the past, and don’t know how to best deal with it.

Any advice much appreciated.