You can get good at anything.
What you need is consistent progress.
Persistency.
Don’t focus on the intensity of the work you put in. Focus on the consistency.
Focusing on intensity will keep draining you in two ways:
Mentally obsessing over that you've not reached the end destination
Mentally and physically, due to the intensity of your effort
Focusing on the consistency will inevitably get you to your destination.
You begin slow. Over time, you increase the intensity.
You never drastically increase it. This way, you ensure your body and mind get used to the pace. Focus on getting your body accustomed to the new pace toward your destination.
Consistent progress over time is key to accomplishing anything.
Consistency beats intensity! Showing up every day is the key to success.