Ah I’ve not had experience of the waking up regularly type insomnia you describe. Sending best wishes I hope the medication does begin to help. And try to be as compassionate to yourself as you would to another person with this illness. 
When I first fell ill with CFS I was prescribed Sertraline (SSRI), although I wasn't keen to be. However, the Dr made it clear they wouldn't consider any other engagement on my symptoms unless I did.
Maybe ask if you can try nortryptiline it’s supposed to be less of a sedative hangover.Just as a quick update, I stuck with the amitripi-wotsit for another week and then took myself off it. My sleep then got worse and I realised that a lot of the pain in my legs and arms had gone away whilst I was on it. My HR hasn't dropped so it wasn't causing that. I'm giving it a few weeks without it but will probably give it a go again if I can't find away of 'solving' my sleep issues without it (or get fed up with feeling like I spent the last few days working on a chain gang). In short, it was doing what it should do for me and with no apparent side affects (once the dry mouth had gone).
If you feel groggy in the morning, try taking it earlier in the evening. I find two hours before bed is about right (its sedative effect usually lasts 10 hours, but if it's lasting longer for you take it even earlier).Had an appointment with the GP last week, she was great as usual. Have agreed to try the ami-stuff again as my sleep is awful, and to stick to it for a couple of months (unless any serious side affects of course). She has also prescribed me some beta-blockers to help manage the heart rate issues (which I seem to get anyway even when not on amy-stuff).
Will see how it goes this time.
This tweet by the UK Royal College of Psychiatrists about their realisation that there is an antidepressant withdrawal syndrome and that it can last several years was posted by @rvallee on another thread:
Wow. Impressed by the RCP I am NOT!
How many years have they been ignoring patients on this subject, I wonder?
His meds caused him some agitation that could only be eased by constant movement, rocking, pacing the corridor etc. He got no peace sitting still.
This is a common drug still and shares many qualities with antipsychotics (they share similar neurological and receptor pathways) and with some antidepressants like SSRI’s.I've had this reaction to metoclopramide. The first time I was given it was as an anti-emetic during surgery in the mid-90s being done in the private sector.
Antidepressants and antipsychotics
Evidence from five randomised controlled trials were identified for antidepressants. Three trials (single trials on the serotonin-norepinephrine reuptake inhibitor (SNRI) duloxetine hydrochloride, the monoamine oxidase inhibitor (MAOI) moclobemide, and the selective serotonin reuptake inhibitor (SSRI) fluoxetine) were compared only to placebo. One trial had four arms comparing fluoxetine and exercise control, graded exercise and placebo, fluoxetine and graded exercise, and placebo and exercise control. One trial compared fluoxetine to amisulpride (an atypical antipsychotic). All the evidence very low quality and the majority was based on single small studies. No evidence was identified for mortality, cognitive function, sleep quality, activity levels, return to school/work, exercise performance measures, care needs and impact on families and carers