As long as your tama is still working fine (i.e. no other serious glitches) it's no big deal. I've had one get down to one pound before and he was fine, so don't worry.
don't worry nothing serious might just be a little glitch no need to freak out as your tama is still working fine it will be o.k just keep feeding it and it will be back to normal hopefully hope i helped bye bye!!!
First of all, what do you mean by "my tama just went on match maker..."? Do you mean that your Tama recieved a visit from the Matchmaker, or your Tama became the female oldie(Otokotchi, the Matchmaker character)?