I find that setting smaller goals throughout the day helps me stay on track and not get overwhelmed. I also find it helpful to have someone else hold me accountable to my deadlines.
If your industry has quite figured it out all the way through every kind of task, you have to pick the average time of what it takes for each of them, and then you may have an accurate estimation of what the deadline should be. But if you are on a journey that is quite new to you or the product is quite innovative, deadlines are gonna be pretty much useless to you!
Atomicons