Just wanted to echo what most of the others have said. Those first few weeks can be so hard, but they do pass. DD2 is 16 weeks old today and whilst I can vividly recall the sheer exhaustion of those first few weeks, in many ways they now seem like a distant memory.
It is quite normal in the first weeks to spend ages feeding, but it doesn't carry on like that forever. As your son gets bigger his stomach will grow, meaning he can consume more milk at a feed and go longer between feeds. Also, he will get more efficient at feeding, so the length of each feed should decrease.
The lack of sleep bit is hard too. Dh never got up in the night either. But he would always let me sleep in at weekends, which helped to charge me up for the week ahead. Maybe you husband could do that for you? Perhaps he could take your son out for a walk or something so you get a bit of rest and some time to yourself. When bfing is a struggle, it can be a small blessing to have LO out of the house for a while, so you know you are not going to be disturbed. It can feel bloody relentless at times, I know.
The other thing that helped me at nights was sometimes just "going with the flow". It's the middle of the night, baby is wide awake, you are wide awake, albeit knackered. Use that time - maybe to do a bit of housework or sort out the washing. Let ds sit in his bouncy chair and watch. He'll probably be starting to get sleepy within 1 1/2 to 2 hours of waking up, so put him (and yourself) back to bed then. Hopefully you'll feel more able to relax in the daytime if you feel a bit more on top of your chores.
I remember feeling a lot like you describe when dd1 was born. I got through it by setting myself targets - a week, 3 weeks, 6 weeks, 6 months and so on. I made a deal with myself that when I reached say, 3 weeks, then if I was still fed up I would change to formula. If you had said to me in those early days that I would have got to 18 months, I never would have believed it. I suppose that, when I was really hating it, it didn't feel quite so bad if I could feel like the end was in sight.
Anyway, I think I've been rambling a bit too much here. I hope you manage to have a good night out. (I bet you'll spend the whole time talking and thinking about ds.) And I hope you decide to do whatever is right for you.