Should I pitch a new role in my current department?

Trying not to make this too lengthy while still giving necessary background... I received a promotion in October that was long overdue part on me for not fighting hard enough, then being out on maternity leave, a merger, and part on my boss for not being willing to move me up earlier due to "HR reasons" that people can't move up that quickly. At that time I didn't receive the salary I had wanted and I voiced that. There were talks I would be moving more into the strategy side of the business, something I was excited about. Then November came and we underwent layoffs. I remained on the team, gratefully due to my role being positioned as a more essential role and my personal skills and ability to move into other roles as needed. This meant I took on the highly tactical hands-on work of a colleague who had been laid off. We also underwent restructuring, my boss was promoted to director level and my colleague, who became a close friend, who I have worked with for the past 4 years was promoted to be my supervisor. This transition has been extremely hard. On one hand I feel over capacity which normally does not phase me, except I know I am not delivering on the high level strategy pieces I had wanted to focus on and what the team needs. On the other, I feel deceived in a way. My boss had frequent conversations with me on how we can get me ready to take on his role when the time comes. This move to be placed under my coworker feels like a demotion in my mind and a lack of confidence in my ability. I want to take control of my career and grow. I have 3 options in my mind... 1. Apply for and move into a new position within the organization -- I have been speaking with the hiring manager who wants me to apply and had me meet with other members of the team. 2. Apply for positions outside the organization -- I have started to look. 3. Pitch a new role to my employer -- I thought of an idea to pitch a new role to my employer focused on the strategy and operational needs the team has while removing myself from the more hands-on tactical work. I have typed up a job description and what I plan to deliver on, however I want to find a title and the salary range for that title. The title needs to be somewhat standard as we have consolidated titles across our organization and HR isn't keen on adding new ones. --- Is this a crazy move? How likely is it that I can pitch a new role that would move me out from under my colleague and ask for a significant increase in salary after just receiving a promotion in October? If so any tips on how to find the right job title? I'm concerned it matches my job title now, but my current duties and pay don't match the work I'm proposing... Help!! I feel like I'm going in circles and talking myself out of it!