I go to a studio, at the studio there is no talking allowed in the hot room, and everyone is very focused on them selves. I think that really helps me to discipline myself, plus I'm a bit of a " don't want to break the rules" by nature, so I will do my best to keep quiet and calm in the room. It's not always easy tho, there have been times when I let out giggles in a very quiet room of people practicing.
At first it was very very hard. I didn't believe I could still my mind at all. I still have to drag it back into stillness when it wanders, but I know I read that even monks minds wander while meditating, I think that's why it's called a practice, because you are simply always practicing.
Going to the studio keeps me motivated and disciplined. You feed off the energy in the room, which I find great. It's a calm peaceful energy, versus hyper chaotic. It gives me more dicipline at home too.
I usually practice around 7pm, that works with my schedule and kids, and gets me relaxed for the evening, which I need help with most. Bikam yoga is exhausting enough that my body really is tired after. If you are having problems with boundless energy maybe try a yoga style that is more physically demanding. I don't love the heat and humidity in the room, it's a bit much, but it takes all my mental and physical effort to stay in the room with 100% effort for an hour and a half. Then I go home and die
Just keep Practicing and it will become easier, promise. You'll reap the benefits as long as you are doing, no matter how many times you have to refocus.