Oh, I didn't know that Thrush was an infection otherwise I would have made the connection.
Excellent, that just leaves me with
"Members at their thickest, linking Trump's inauguration with really good times" (6)
I'm guessing Trump's inauguration means the letter "T", but I have no idea what the definition is
"Sexually active? There's danger engaging in extremes of fantasy (6)"
No clue
and
"Very turned on by Ray's cooked sole" (8)
I think the answer could be "Salutary", based on the letters I have already (S?L?T???), ray cooked could mean jumble up the word ray and turned on could refer to good health, but I'm not sure