Hi, I'm in a similar situation to you - ID twin girls 10 wks old, and DD1 2 yes old. I've looked at your photo, and they do look quite different, but I've read that even identical twins aren't always identical looks wise (just gene wise). Our girls definitely are identical - shared a placenta and amniotic sac, but were quite different sizes when they were born, and still look quite different although they are becoming more similar. I presume yours had separate placentas and sacs, so they couldn't tell you if identical or not. The only way to tell for sure is to wait and see how they look as they get older, or have a genetic/DNA test done - not sure how you go about this? Also, are there twins in your family? Non-identical twins are hereditary, ID twins aren't, which may give you a better idea?
As for a routine - I can't really help much! I'm bfing on demand, and they tend to feed every 3-4 hrs at the moment (are going up to 6 hrs some nights). They tend to have lots of naps during the day (from 30 mins - 3 hrs approx, no pattern) in their bouncers or downstairs cot (or car seats if we are out), but I haven't started a "proper" daytime sleep yet. At night i put them to bed about 9.30, and sometimes it can take up to 2 hrs to settle them down! Once one settles, the other seems to wake! They don't seem to disturb each other yet, and they still share the same cot. Do yours share a cot? If so, is it worth putting them in separate cord first, before you try separate rooms (less running around!). I find having 2 definitely takes up more time. I run a business from home with DH, and found with DD1 I could still get quite a lot if work done while she slept, with our twins I can't! It seems by the time I have fed them, played/settled them, sat down for 5 mins, that it is time to start again! And that is with DD1 in nursery 3 days a week!! Were yours prem? If so, I think it can take longer to get them in a routine?
I'm not sure which feed to replace with formula, as I think taking any feed out will reduce your supply. Maybe replace the bedtime feed do you know how much they are getting? I find the hardest thing with bfing is knowing they have had enough (but do find it easier than having to sterilise bottles each time!!)
Tummy wise, mine is a bit "goosey" looking too! It had to stretch more for 2, and second time around has less elasticity I think, so I'm sure it will return to normal, it may just take longer. We may have to leave it a while before we can wear a bikini again!!
I hope things start to feel easier for you. My girls have just started smiling, which melts my heart every time! As you say, there is light at the end if the tunnel!! :)