Baby - you may find the weight loss is due to stress. You are anxious due to hormones and / or depression, then you are anxious because you are anxious. Added to this, poor sleep leading to exhaustion etc. You become stressed because you are worrying, understandably, burning up all the nervous energy not understanding what on earth is happening to you. AD's can take a while to work and sometimes you can feel worse before better.
Please be reassured that you are not alone and all the symptoms you are experiencing due to meno/depression/anxiety/insomnia are normal even though it feels horrific. Maybe, as CLKD says, get your weight checked at the surgery to put your mind at rest. Have a read at Professor Studd's site, he goes into great detail about peri, meno, HRT and reproductive hormonal depression which you can be prone to if you have had PND before. Don't be so hard on yourself, I know it's hard to see the wood for the trees but I am sure once your hormones are levelled out and the AD?S start to work you will feel a difference. Has testosterone been suggested to you, may help with the fatigue / exhaustion side of things ...?