I would strongly caution you AGAINST self diagnosing your husband. It creates labels in your mind that require him to accept specific treatment that may not be appropriate. His psychiatrist, who is appropriately trained and educated on this subject, may not agree with your diagnosis and thus you have set your husband up for complete failure. (He can't make you happy by taking meds that his doctor doesn't agree that he needs.)
ANYONE can behave in a manner that suggests bipolarness under the right circumstances. We all have ups and downs. You are jumping to a conclusion based on one example you have seen.
It would seem that his psychiatrist is more concerned with anxiety than depression, based on the medication he is prescribing. Anxiety can easily manifest itself in a way similar to mania.
I think perhaps you should attend therapy with him...not to tattle or demand the type of treatment you believe he needs, but so you can talk to the psychiatrist along with your husband and get a better understanding of what the doctor thinks is going on.
And, if your husband is really dealing with anxiety, leaving him while he is seeking help from a professional is just cruel in my opinion. Work with him, don't add to his stress by leaving him and possibly impacting his relationship with his daughter. No one ever promised marriage would be easy...that whole "better or worse," "sickness and in health" stuff...well, this is worse and sick. Hang in there as you promised to do.