Life is only understood looking backwards. Unfortunately it has to be lived moving forwards. This is a paraphrase of a quotefrom Danish philosopher Soren Kierkegaard. What do we do when the path we are on includes a door which seems locked?
I am not advocating changing paths especially when one feels a powerful connection and desire to pursue a specific goal. I'm merely suggesting a different approach. Try looking elsewhere for a path/doorway which is more amenable to entry.
This may manifest itself in changing a particular tactic you are using. Re-evaluate your methods, for instance. Look to meet new people associated with your goal. Consider changing your geographical location. Perhaps a literal change of scenery will re-invigorate your efforts.
Your frustration in facing a locked door is a message. The Universe is blocking you for a reason. Perhaps it means going back to school or seeking more experience before approaching this same door.
The possibilities are endless. Just be aware that when the you find a door that opens more easily, enter and continue your journey. It is very likely that this is the right path for you.
Remember the concept of flow. It feels natural and you get where you want to go. The open door leads you there.