Rocky's Owner

Dear Forum Members, I'm hoping someone may be able to assist me. My budgie has blood on the top of his head, which I have a suspicion may be because of mites. I have been applying some Anti-Parasite (Ivermectine 10ug)drops behind his head in the past which has seemed to work, except this time it doesn't. I thoroughly clean his cage every week so I'm a little sceptical it is mites, however I read these drops treat a number of different mite and worm problems so I use them. I only have one single budgie. He's not his usual active self, doesn't fly well, pants for breath, and looks "old". He is around 10 years old, so he is I guess an old age pensioner as budgies go, though I need my little mate around as long as I can have him. Does anyone have any tips on what I could do? regards, Peter