Sometimes having all the time in the world doesnt mean that you sit in the studio everyday and write stuff. A balance has to be sorted and an individual system that works for YOU with how you use your time and stimulate creativity.

I once worked full-time and had the same problem. When I stopped working I found that I couldnt write everyday. So I went and found a good paying part-time job. Now I have a balance that allows me space from the studio enough to build up a creative splurge so that when I have a day off (and the g/f is at work) I can get up early and write all day (which is plenty of time to get out a track).

While at work I can think about a track i want to write and get a clear picture in my head about how I want to do it.

Another way I learnt is to use what little time you have free to do all the little things before you put down the track proper. By that I mean, select samples and riffs or patches and put them all in a folder. Just work out the elements for the track little bit at a time. Then when you have all the pieces a day will come when you can sit down and quickly lay down the track to about 90%. Then spend what time you can doing the polish up thing on it and before you know it its finished and you know its spot on ;)

The anxiety of not having the time available is the hardest thing to overcome as it can make you procrastinate.

Also, working like a dog is not good for anyone no matter what. Maybe you should first consider why you are doing this and at what cost??