I could totally relate to your post. Lots of it hit home with me as well. I too work full time and at times find it very overwhelming. Just this week was one of the tough weeks, which was why I reached out on my computer to some form of community I could find. I was happy to find your post. Nice to not feel so all alone.
First of all you have to appreciate that as people who have bipolar we are the minority who hold down full time jobs. Most folks are not able to do that. For some of us it is a massive necessity because we need to keep the roof over our heads and food in our bellies. Getting up everyday and going to work is a huge step forward in my recovery. And that is how I think of each day. And sometimes I say to myself out loud "I am so proud of you." "You are doing what most people with this illness can not do." And as crazy as it sounds it makes me feel better. I know I am the exception. And that doesn't make me special in anyway. It just means that where I am in my recovery I am able for the most part to work. I feel like a contributing member of society. Which is really important for me in my quest to feel "normal".
It does get tougher when you are not sleeping. It is such a delicate balancing act with our damn meds - I get that. I can't make plans in most evenings because of my med schedule. Heaven forbid if I forget to take my anti-psychotic at the right time. Throws my whole program off kilter. Not sleeping on a regular night becomes a huge issue on those nights. So some of those mornings I may be in a little bit late. But I stay later on those days to make up for it. I know I can't take advantage of my employer, but I will tell my boss that I am having trouble sleeping if there is a really rough patch. Thankfully I have one that understands.
I have found that one of the big keys for me in recovery is that I need time to myself to do nothing. As in no demands on me and my time. I use that time to journal, go for walks, watch some mindless TV, read or listen to music.
I would caution you on taking a course in the evenings. You are already feeling overwhelmed so I wouldn't add yet another demand on your schedule. Even if it is something fun. Or if you really do want to do it book it on the weekends when you may have some more free time. Personally I have found that if I have no free time my moods shift. I purposely avoid activities because I know I need space. I still am sure to make time for friends and fun, but it is totally on my schedule. I do not let anyone dictate to me how I will spend that time. And for me who has lived a life out of control for so much of it, that just makes me feel a little more powerful. Being in control is the big part of this illness for me that makes me feel well and healthy.
I don't know if any of this will help. But I do know how you feel. And it is incredibly difficult to hold down a full time job with this condition. No question about it. But you are doing it. Sure there are hiccups along the way, but for the most part you are getting there and doing it. And people without bipolar have moments when they lose their temper.
Best advice I ever heard was to be gentle with myself. Curb the negative self talk. Stop beating ourselves up all the time. Try not to focus on all our weaknesses. Think of things on the positive side. In other words be gentle with yourself. Hope that helps.