1-1.5 hours of weights PLUS 45 minutes of cardio at one go is a huge amount of work, ESPECIALLY basically going from 0. I would say overtraining is very likely.
I would hazard a guess that if you went from nothing to that regimen, you are not having the best sleep in the world either. You may be sleeping, but it is probably fitful and not good rest, which can exacerbate depression.
You might try doing 1-1.5 hours of lifting on one day and doing the cardio on the next. Do that for 4 days, then take a rest day where you do some hiking or walking. And give yourself one cheat day a week-preferably on one of the days you either lifting or running.
One thing I learned about over training (for me) is this. For cardio work, I generally run. 4-6 miles depending on speed and what else I have going on. I found that if I was running long distances the day before I did the lower body workout, when I went to run the day after the lower body workout, my legs would go into complete revolt after about a mile-if not sooner. I would be exhausted, and it would take me a few days to get over it. So now, I don't run as much before I work my lower body, and I always take a rest day after.
Take smaller bites. Once you are up and running and physically active again to the tune of an hour or so 5-6 days a week and not exhausted, then you can look at fine tuning things to get the best results.