Which Choices Make Us Happy?

As I was watching this presentation about the abundance of daily choices in today's society, I was amazed how much every point relates to me and the way I feel about my choices. Partly it felt good that I am not the only one who feels so confused about taking the right choice. I guess it makes sense that I do like it more when I sit in a restaurant and I see 5 dishes on the menu instead of 25. I am indeed better off when given less choice.

Do you also feel that this presentation applies to your experience?

However, there was one more point which complicates my choices: karma.
Here is the Google definition: "(in Hinduism and Buddhism) the sum of a person's actions in this and previous states of existence, viewed as deciding their fate in future existences."

I feel that every choice for me is like a position at a cross road. Should I take a particular job? Should I have a baby? Should I take this flight or the one on the next day? I sometimes feel I am moving on a map of my own life and each choice is leading to very different possibilities later on, which I do not know about. I always feel one of them should be more right than the other and it is bugging me so much that I often delay immensely the act of choosing. This makes me unsatisfied and irritated with myself.
So if we make a choice, is our path further on pre decided?
Is our life pre written or we can write it down?
I think I have to make a choice what I decide to believe and move on. Because even if our life is pre written, our choices are also dictated by that scenario, so no point thinking too much, right?