Ooh, sorry Beautiful. I fell asleep
My dh works very similar hours to yours - ie every evening as well, and it is only since the children have got bigger that he has started having time off during holidays. I do so know how you feel, feeling that you have all of the responsibility. It is exhausting, isn't it?
The scheduled once a week/fortnight lounge around in the bath, with magazine, is a great you-treat. Similarly I learned to plan for an early night - 8.30/9.00 pm - with a good book or just for 10 hours sleep - once a week. It's amazing how different the world looks with some decent sleep under your belt.
Can your dh have an evening off at weekends? If so, can you plan for a nice meal, glass of wine/DVD/massage session with candles, if you aren't able to get out/meet up with friends? Make a social event of it. Dress up a bit, light a candle, feed each other strawberries dipped in melted chocolate for pudding. Spoil yourselves. This is the tough bit. It will get so much easier once your ds1 is settled in full time schooling and disappearing off on sports days during the holidays. It is now that you need these extra treats/pampering. (And I found that if you make the effort to pamper your dh occasionally, even if you feel exhausted, it does tend to help, as he might return the compliment.)
I also found life easier once I stopped expecting dh to be able to help out. Like you, I had hoped that he would be bursting to spend time with us/suggest creative ways to spend an hour at weekends with the boys etc. It wasn't ever going to happen. Assume that you need to pace yourself to do it all and avoid looking at other couples whose dh's seem to do a lot with the kids. It only makes you feel worse to compare your lot with theirs, and besides those couples often have tensions/problems which you just don't see.
As Bluecow suggests, I found it helpful to try to structure my days/holidays with the kids, in advance. You don't have to stick to the structure, but it's there if you feel at a loose end. Have a daily/weekly timetable on a sheet of paper and have a list of things for each day:
art hour/painting/papier mache making,
trip to the library (twice a week in hols), swimming trips,
walk to the park/playground,
cooking session - can include sandwiches, cakes, jelly, pancakes, fruit salad . . . .
lunch,
den-building session (under table covered with sheets),
CBeebies/MN hour,
welly walk/puddle jumping/duck feeding,
indoor hide and seek combined with tickling session when you get found,
buy a 99p bag of popcorn from the supermarket and turn a DVD afternoon into a home cinema event,
face painting,
early evening disco (30 mins boogying to favourite music is a great tonic!)
For a boost to social life, I also found joining a book group useful. We only met once a month, so not too much strain on dh to look after the kids in case they wake, but you get the book to read too, so giving you something to do in the build up to the meeting. Choose your bookgroup carefully. Some are very intense. Others focus more on the chocolate/wine/chat and talk about the book as well
HTH - don't forget to build in an hour a day on MN for you at least! It keeps you sane, when all else is failing.