Talk to him about it,express your desires.If he simply does not like performing oral sex on females,then that IS his preference.You can't force him to give you oral sex and he shouldn't be pressured to do something he doesn't want to do.Some people just do not like giving oral sex,and they should not be condemned for feeling so.
There's no point in doing something you don't want to do(That goes for everyone,whether sexual or not) even if it would please you,if he doesn't like it,he doesn't like it.
And you obviously do not like swallowing or else you would not have used it as a defense,if you did,you wouldn't through it out like that.
Are you wrong?No,not at all.Men are not the only ones who can enjoy oral sex.Perhaps suggesting he do it to you before you give him oral sex would help with his "headache" excuse.
Talk to him about it,the most we can give you is assumptions as to why he doesn't do it.
I know a bunch of crazy chicks are about to answer saying "just don't give him oral" but using sex as a tool is unhealthy,not to mention,if you genuinely enjoy pleasing him,why would you stop?
Talk to him,tell him you would love for him to give you oral sex.If he says no,ask why,his reasoning,if there's any thing you can do to alleviate his reasoning(if it ends up being taste or odor) and try to compromise.