There are quite a few signs that you may be Bipolar by what is described in your post but of course only a licensed certified psychiatrist could properly diagnose you. Keeping that in mind I see several indications that seem to suggest that you may be Bipolar.
First, many times people who have Bipolar often are misdiagnosed or have a dual diagnosis of ADD. Secondly, when put on antidepressants, somebody who is Bipolar will be thrown into a manic episode. Other things that pop out are the mood swings that you are experiencing. Somebody who is ADD will not have suicidal thoughts or the mood swings that you describe.
I think that it is wise that you go to the Mental Health center to be evaluated. Bipolar is a treatable illness and the longer it goes untreated the more it worstens. Being medicated will restore the chemical imbalance that makes it difficult to live a stable and happy life. You owe it to your wife, family, friends and most of all yourself to make sure that you take the medications that are necessary to keep you well.....for it is far more dangerous for somebody who is Bipolar to remain unmedicated that it is for them to take the meds that are necessary for the rest of their lives. Many people who are Bipolar put themselves and others at risk when they are unmedicated with the impulsive risks they take and the suicidal thoughts that take over. PLEASES do not make the mistake of thinking that you can go on without medications as many who have Bipolar do. IF you are diagnosed and the doctor puts you on meds please take them. IT will save your life and will preserve your marriage and all your relationships with friends, family and anyone else you interact with.
Good luck with everything and please keep us posted with how things go with your Mental Health visit.