Do you have a physical job are are your tired from the early mornings? I assume you get to bed early to compensate?
If its not tiredness through sleep then you could be eating too few clean carbs so have a lack of energy. You would be best off sorting a clean diet which will probably see you eating more but of the right things which will in turn give you energy and help you lose weight.
What do you do on the weekends when you wake up early? 5 am is the best time of the day to get out on your bike etc..
Trouble is we get stuck in a rut. If you persevere with cardio you will feel better and more energetic over time. Its hard in the beginning but will pay off.