Hi Fringe,
Sorry to hear about your Dad

and your hassles at the moment. I'm not sure what help I can be, but I thought I'd share my "routine" (ha ha ha - routine so isn't the right word here!). My babies are nearly 5 months old, and my toddler just turned 2 (20 months between them).
Firstly, it took me 14 weeks to have both boys fully breastfeeding, and then another week or so to wean them off the nipple shield, so don't let anyone tell you that giving them bottles will mean you can't breastfeed or get them back on the breast. You can, it just takes a bit of extra effort1
In one month, starting when my boys were 9 weeks, I had gastro twice, the flu once and horrible headcold and sore throat, so was having MAJOR supply issues for a while. I had to completely stop feeding them the first time I had gastro as I had to have Maxalon shots and tablets, and you cannot breastfeed when taking them (which makes me think you were on Mottilum, not Maxalon, to boost your supply). At this stage I was pretty much fully expressing and bottlefeeding them EBM before I got sick - Noah had actually taken the breast for the first time ever the day I got sick - so bottles weren't an issue for me. I was lucky to have a small supply of EBM in the freezer, which the boys had during the time I was Maxalon, and they also had to have formula - which did not agree with them AT ALL, the poor little things.

I ended up comping with formula every time I got sick during this month as my supply just got worse and worse each time.
I found the best way to get my supply back up every time I felt better was to pump before and after each feed, plus put the babies to the breast before they had a bottle. At this stage though, they were so crap at breastfeeding that they could be on the breast for 20-40 mintues, and still need at least 100ml EBM top-up afterwards - and I could only get Noah to attach every now and then. So say they were due for a feed at 10am, I'd express at 9-9:30, then put them to the breast at 10am, then give them a bottle and as soon as they were back asleep (about 11-11:30), I'd express again.

It drove me a bit mental, but I was so determined to breastfeed that I kept going. DS1 goes to daycare 2 days a week, so these days I'd just sit on the couch with a baby on the breast and just keep swapping sides and babies.
I'm very lucky that I've always been a fantastic lactator (too good with my first - I had major issues with him as I had such an over-supply), so I was able to get my supply back up without needing any help other than plenty of pumping and stimulation when I was putting the babies to the breast and lots of warm wet flannels on the breasts when I was pumping. As the other girls have mentioned, there are different drugs and herbs you can try. Also, make sure yuou drink enough water - if I don't drink at least 4-5L a day, I notice my supply drops quite a bit. I found I drank most overnight - I'd drink at least one 600ml bottle of water before and after each night feed, as I seemed to be too busy during the day to fit it in.
Also, in terms of a routine, I've only just started to get one in the past 2-3 weeks (I lie - I had a great routine when I was bottle-feeding, but started demand-feeding when I finally got them on the breast and it all went to *&#@). My boys were feeding every 2-3 hours during the day, and would only sleep for 20-40 minutes at a time and I couldn't handle it, so I decided to get tough and only feed them 3-4 hourly. I try to only feed 4 hourly now, but if they're really hungry, I'll go down to 3 hourly, but never less than that now. Since I've been doing this, my life has improved drastically - my boys are happier, much more settled, less chucky and refulxy and they sleep for longer! I think part of our problem was I sticking them on the breast whenever I couldn't settle them, even though they were tired not hungry, so they were too full all the time, which was making them chuck more and have more wind etc. I also got a bit tougher with settling and sleeping - I don't use controlled crying as such, but I try not to pick them up once they're in their cots (I seperated them into different cots a few weeks ago as they were waking each other all the time and it's helped heaps), I don't rock or cuddle or pat them to sleep anymore and I let them have a whinge. I hate hearing them whinging, and as soon as they start crying, I go in and give their dummies and pat and shoosh them until they're calm, and then I leave again but they can now actually put themselves to sleep without much fuss at all!

If one baby is still asleep when the other has finished feeding, I wake him. I tried letting them do their own thing, but found they were more unsettled and it meant I did nothing but feed and like you, I have another child to look after as well, so couldn't just sit on the couch feeding all day long. I also wake them when they're "due" for a feed, although the other baby will always wake during the feed (my boys are spookily close and nearly always wake if the other one is taken out of the room for more than 2-3 minutes). Usually, they wake at the same time though, and so I feed one "halfway", burp him and then put him on the playmat or in the swing or rocker, and feed the other "halfway". Then I change the first baby, burp him again and finish feeding him, then change, burp and finish feeding the second baby. I've always changed them halfway through the feed (I did the same with DS1) as I have a very fast let-down so they take in a lot of air with the initial half and need at least one or two breaks and lots of burping or else they bring the whole feed back up as soon as I lie them down.

For this reason, I can't tandem feed (and Noah won't attach in that position anyway).
Things are starting to get better now, and I can really see the light at the end of the tunnel now! Now, if only I can get DS1 to start sleeping through the night, I might have a shot at getting more than 3 hours sleep in a row....
Sorry it's such a rambling essay - I'm sure you understand how sleep-deprived I am and therefore how hard it is to articulate anything! I hope it makes some sense and helps a bit. Good luck!