Getting sick after deepthroating??

Ive recently started seeing this guy and every time I have deep throated with him I get really sick for days after. This has happened on 3 seperate occasions. Ive done this many times with other partners and it has never happened before. Just with him. I will give him head, then for the next few days I feel awful. Im talking sore and swollen throat, pounding headache, body aches and chills, nausea, slight temp, congestion, etc. The first two times I thought maybe it was a weird coincidence but now Im wondering if its related lol this may be a stupid question but im curious if anyone knows?? I dont normally get sick very often like this. Anyone know if its possible that its related or just weird timing and a shit immune system lmao TIA