Okay, I hope this isn't too long but I'll add my two cents.
Firstly, as you can see from all these replies, you are not alone in this. Everything you've said I can remember thinking myself many a time, so don't worry that it isn't in any way 'normal' for someone with anorexia nervosa. That said, things can change. The desire to relapse and do it 'better' next time is something which will probably only properly disappear when you give recovery a real go. Until you are able to leave your current mindset - even for short periods of time - you won't see the benefits to recovery and will continue to want to spiral again and again (even though you know in your heart of hearts it achieves nothing.) This is where your consultant's logic comes in; he knows that right now, you're mentally not functioning in a way that allows you to see sense in terms of your ed, so he doesn't want to run the risk of imminent relapse on your exit from hospital. I know it feels horrible, and unfair, and makes you angry - but ultimately all he wants to do is keep you alive.
I've been in an in-patient unit three times in the past five years and believe me, there is so much more to life. You don't state your age, but I'm assuming you are over 18. Admittedly, my IP stints were in adolescent, specialist eating disorder units so if you're in a general adult psych ward things may be completely different, but the principle is still the same. Inpatient treatment is not the solution to all your problems, and it doesn't claim to be, but it is whats neccessary to save your life. It is YOU and noone else who can get you recovered. You can't sit around waiting for recovery to come to you...it never will. You have to make the first move and you have to stick with it, no matter how hard it is (and it will be bloody awful) if you want to live the life you deserve. Sorry if this sounds harsh, that is in no way my intention, but its the truth. An eating disorder will stay with you for life until you decide you don't want it anymore. I know too many people who have left making that decision way too late. Do you want to end up in your 30s, having spent your entire life in and out of hospital, having had no relationships, being infertile, having missed out on a career, a life? I know you don't want, nor deserve, that fate. That is why you have to decide - and decide now - that you want to get better for yourself. I know you didn't ask the doctors to 'save you', but you can decide to save yourself.
I became ill when I was 13 with anorexia and was hospitalised and 'forced' into recovery many a time. All my treatment with numerous outpatient and inpatient services was a facade - I didn't want to get better, I was just doing it 'for my parents' or gaining weight to get them off my back, only to lose it again. I never thought about what I wanted. So, it was only when I left the last IP unit I was in last December on turning 18 that I realised my life was in my hands now. As a nurse said to me, I can either leave and take the path of adult section and hospitalisation, or the path to freedom. I did alot - and I mean a huge amount - of thinking. I wrote things down. I made plans, lists, goals. I envisaged my life in 15 years time with this disease, and without it. I looked around me; I knew too many friends from IP who were wasting their potential, wasting their lives on their eating disorders, making hospital and weight a pathetic competition. And I realised I didn't want that anymore. So, I stopped making excuses as to why I couldn't get better and started looking for ways in which I could. I made the most of my therapy sessions. I threw away my self-imposed rule book on how to eat and started listening to my body (after years of doing the opposite it wasn't easy I can assure you, but believe me it is so liberating when it starts to work!). I went out and started living. I now have a fantastic social life, an offer from an Oxbridge university, a (finally) happy family and a sense of confidence I'd never before experienced. I've managed to maintain my weight at a BMI of 17.5 for 2 months now - the longest I've ever remained stable - on a diet averaging 2600 calories a day. Some days I eat more - yes it IS possible to have 3 courses at a restaurant and eat 3000+ a day and not gain weight - some days I eat a bit less - I've learnt its normal - but on average I'm eating enough to sustain my lifestyle and avoid going backwards again. Apart from never allowing myself to eat less than 2000 calories a day, I have no more rules, no more limits. I feel free, however cheesy that sounds. And yes, I do need to gain more weight and I'm planning on increasing to a BMI of at least 19 (which will involve shoving calories back up to 3400+), but considering at one point I was near death with a BMI of 12, I think its pretty good going. Basically, you can get better. Things will improve. It takes time, effort and support, but its possible. Please don't give up hope or give up on yourself. The fact that you know at some point you want to recover is proof enough that in your heart of hearts you want to be rid of this. Just think about whether its in your best interests to get the hard work out of the way now...or in 20 years time, when it may well be too late.
Good luck, and take care.
xxx