Tired Of/from Not Sleeping

For about 9 months or so I was getting up almost daily at approx. 4:30 a.m. to go work out. Toward the middle/end of summer I cut it back to 2 to 3 days a week and would sleep "in" the other days till 6:00. Except I keep waking up around 5:00 a.m. and then doze on and off until my alarm goes off. I am still tired at 5:00 so I don't get up then. I work full time so naps for me are not an option. I fall asleep fine, but would just like to sleep until the alarm goes off. because of our schedules, kids don't go to bed until approx 8:30 (they are still getting plenty of sleep, and for a whole host of reasons, an earlier bed time is not practical) so I don't unwind until after that. Spend some time with hubby, and typically don't go to bed until about 10:00 or 10:30. I have had my thyroid tested SEVERAL times over the years for many reasons and it always comes back fine. I expected my body to kind of remember that I got up early for so long, but I just want to sleep. ADDITIONAL INFO: My husband and I work full time; his job is commission based, my job has the insurance. I leave at 7:50 to take youngest to daycare; work 8:30 to 5, pick kids up from daycare (closer to MY work than his) home by 5:45, lucky to have dinner on the table by 6:15 depending on the day. That is a day with no activities and with husband home to help. I work out in the morning b/c my kids sleep till 7;15--works for them/us. I go to the local YMCA--up at 4:30 to get dressed and get to the Y at 5 a.m. for the class I LOVE 2 days a week (in summer I could sleep a little later and run at home on the other days, refuse to do so in the dark, no street lamps where I live) while husband and kdis still sleep, home and in shower by 6;30, ready to get kids up and going at 7;15. Working out AFTER work will not work--I would NEVER see my kids (and they are not morning people, so changing their schedule is not so practical)--I wouldn't get to the Y until 5:30-ish at best and not home till after 6;45 and then eat. I HAVE to shower after a work out--I sweat like crazy, and working out late does nothing for helping me GET to sleep later; and when I do get up for a morning workout, I feel better for the day. I am not one to be able to work out at home--the classes at the Y keep me on track overall (or daylight in the summer to run outside) I stopped working out as many days b/c I was pregnant and figured sleep was just as important. Then had a miscarriage, some expected depression and lack of ambition and a lot of other personal stressors in my life and decided I was running myself down, hence the choice for more sleep. Trying to drop a few extra pounds (the last few stubborn ones) b/c I am between pant sizes--one size is too tight, next size up looks ridiculous on me--I've tried MANY stores, brands, styles, etc. SO I figured maybe I needed to shift my metabolism, let my body rest and my body might stop fighting me on the last few pounds (worked after pregnancy the first 2 times to cut back the cardio/increase the sleep once baby was sleeping better--dropped 10-15 pounds very quickly with more sleep at that time). My prior workout schedule did not include any rest days, and I know that is important too, so I added the "off" days to sleep/recover. SO, now I'm rambling and as you can see there are many factors involved here. Bottom line, I feel I NEED more sleep. Many days I set the alarm to go to the Y and I am sooooooo tired I reset the alarm to an hour and a half later just so I can sleep some more.