If you are the creator/owner of a channel, then you should be getting opped (@) instead of voiced (+) - However, if you prefer to be voiced, then you should be able to obtain op status through the bot? Or through some sort of channel service? (e.g. ChanServ). If not, and you can no longer obtain op/voice status then and you have no channel service, there is not much you can do.
If you do get op status, just use /mode #channel -o+v yournickname yournickname to voice yourself. You could also ask a friend who is opped in there to voice you.
Regards,