You cannot work without a deadline. It doesn't matter what you do, set a deadline. If there isn't a deadline, then it will inevitably stretch and consume all your valuable time.
The deadline isn't for putting pressure on you, contrarily it is for relieving you of pressure. I am replacing thoughts like "I couldn't do within a dealine, I better just give up."
with "I couldn't do it within the deadline, let's sit down calmly and analyze what went wrong." or "Ok, I will come back to this later. I better do the other more important task.".