You have had them for six months and they were probably only six to nine months old when you purchased them. I forgot to ask you how large they were when you bought them, but chances are they were less than 12 months old.
Since you have only two of them, they will both reach sexual maturity: the larger one will become a sexually mature female (happening right now) and the other one will mature as a male and stop there.
If you had three or four of them, the largest would mature as a female, the next in the pecking order would mature as a male and the remaining other(s) would remain sexually immature. If, for whatever reason, the female were removed, the male would become female within a week or two and the next in line would finally reach sexual maturity as a male.
If you were to remove the male from the group, the ranking sexually immature fish would reach sexual maturity as the new male. Nobody moves up the ladder unless there is a vacancy. In nature, you may have three or four or five Ocellaris clowns all residing in the same large host anemone; however, there will be only one female and one male. The others could remain sexually immature their entire lives.
Getting back to your situation. Your female is reaching sexual maturity, which is demonstrated by her behavior. In the next phase, they will be more accepting of each other and then, in the final phase, they will bond as a mated pair. If conditions are right, they might even spawn. The female will lay the eggs but the male will be charged with fanning them with his tail. In nature, that cycle could repeat itself every couple of weeks.
P.S. -- One of the reasons the female keeps the male cornered is to make sure that she gets more to eat than he does. She doesn't want to take any chances that he might get to grow as fast as she does and threaten her dominance. Once she is secure in her status as the boss and satisfied that he has acknowledged her superiority, things will calm down.
