Getting A Database Locked Error When Using Golang and SQLite - sqlite

Question

I'm experiencing a database locked error in this piece of code.
The thing is I already wrote pretty similar code to this and I wasn't getting any errors.
But now when I run it, I get a Database Locked Error with the error code 5.
The error occurs on the tx.Commit() statement.
Here's the code itself:
type UserRepository struct {
db *driver.QuestionlyDb
}
/*
Creates a new user sql driver that executes user sql statements on the sql driver.
*/
func CreateUserRepository(db *driver.QuestionlyDb) *UserRepository {
return &UserRepository{db: db}
}
/*
Create a new user row in the database.
*/
func (ur *UserRepository) CreateUser(u *User) error {
tx, err := ur.db.Begin()
if err != nil {
return err
}
stmt, err := tx.Prepare(`INSERT INTO users (id, email, password, username) VALUES (?, ?, ?, ?);`)
if err != nil {
_ = tx.Rollback()
return err
}
defer stmt.Close()
_, err = stmt.Exec(u.GetID(), u.GetEmail(), u.GetPassword(), u.GetUsername())
if err != nil {
tx.Rollback()
return err
}
if err := tx.Commit(); err != nil {
return err
}
return nil
}
The database connection is created in the following way:
type QuestionlyDb struct {
*sql.DB
}
/*
Creates a new database connection.
*/
func CreateDatabase() (*QuestionlyDb, error) {
db, err := connectToDb()
if err != nil {
return nil, err
}
sqlDb := &QuestionlyDb{db}
return sqlDb, nil
}
// TODO: Set db name as env variable
func connectToDb() (*sql.DB, error) {
db, err := sql.Open("sqlite3", "./questionly.db")
if err != nil {
return nil, err
}
return db, err
}