I have never posted before but reading about your situation, I had to respond. My husband is bipolar type 2, and prior to his diagnosis 2 years ago, he drank constantly - he said to deal with the suicidal thoughts that were intruding on him every few seconds. I finally gave him an ultimatum and told him to leave and get sober, or he was not welcome to return. He did, and he stayed out for 3 months and attended AA regularly, and seemed to be on track. He visited us (we have two children, currently 2 and 5) and was sober whenever he came to the house (a condition I required for him to be here).
After this time, he came back, continued with AA, but continued to be very depressed and feeling suicidal. He then got diagnosed as bipolar type 2 (which seems to me to be bipolar without the mania phase - instead, he gets anxious, irritable and agitated - starts things and doesn't finish them, low frustration for the kids, unable to sleep, etc). He started on a mood stabilizer, in addition to the 2 antidepressants he was taking, and within 2 days, he was back to the man I met almost 20 years ago. He said he felt "normal" for the first time in years. His mood improved, the suicidal thoughts disappeared, and he was a great husband and father again.
THEN he decided that his problem had been the bipolar, not the alcohol, and started to drink again. He told me that his drinking in the past had been his way to self-medicate, and since he no longer needed to do this, he could have a few social drinks once in a while....
A few drinks led to more drinks, to "black outs" and to absolutely irresponsible behaviour, including driving while intoxicated, and sneaking in alcohol on nights he was supposed to be watching our kids. We tried everything - limiting his alcohol to 6 per week (he snuck in extra), letting him drink whatever he wanted on evenings where I was available to be sole parent to the kids but NO DRINKING when he was on daddy-duty (he drank when he thought I wasn't looking), and repeated promises to change. He drinks more than a case of beer a week, seems to have no control over it, and blames me for making an issue of this.
I have now told him to get out. He is coming up with all kinds of plans so that he can control his drinking and wants me to reconsider. I won't - I've told him I need a minimum of 3 months sobriety before I will consider him returning home. Will this be hard on the kids? yes - but if he visits us regularly SOBER, the kids will have a "dad" instead of a body in the home who is physically present and emotionally absent or angry.
Trust me - we have had hundreds of discussions and it is only when I told him to get out that he is again going to AA and taking this seriously. I've also informed his family and friends, who are helping to hold him accountable.
You need to do this, for yourself and for your kids. He can visit when sober - you might be amazed at how much more positive your relationship becomes when you only see each other when things are good!
But, just as a warning, you need to consider if he will lash out at your and/or the kids when you leave or tell him to go. I recommend having a bag of spare clothes, $, toiletries, spare keys, important documents and other necessities packed and in the car at all times in case you need to leave quickly. And go over a safety plan with your kids - who to call, where to go if needed, and a list of emergency numbers. Have a cell phone if you can, and if you are planning to deliver an ultimatum, let a friend know who can call you or drop by to make sure all goes well. Have a code word (i.e. "chocolate") that you can use with friends or family if you need help immediately. You may want to move money from joint accounts into your own account - bipolar is known for excessive spending.
If you are worried at all about his suicidal threats, call his doctor or take him to the hospital for an assessment. Know that sometimes this is an emotional blackmail technique to make you stay.
Good luck, and stay strong. Your children need this from you, and one day, your husband will thank you as well.