Exhaustion comes from exertion. Fatigue is the hallmark of experience. Be happy when you feel like this. Tired just means you did something.
Aches and muscle pains come and go. The more you use them, the more you can do. It’s moving now, need to keep on pushing. As much as you want to stop to rest, don’t fall into the trap.
Keep on pushing until you see the work meeting the goal. Don’t fret about how fast or slow, don’t worry about the unpleasant tasks needed to get where you want to be. Do the necessary dirty work to achieve the aspiration.