Collette, I'm like you, I do tend to get over enthusiastic.
I had to lose 4 stone to get to where I am now..10 stone (and have been for 12 months too..yippee!)I started with swimming and bodymax, but did go 4/5 times a week, building up to the 5k swimathon.
Since then I decided this regime has to be for life. So, rather than doing something daily, have fitted in less sessions but they are quality ones and always (bar an emergency) take priority.
What I have found with juggling 2 nippers, self-employment, and an unwell husband, is that it gives me time to unwind, de-stress, and keep fit but the other 'demands' know I shall be out during these times.