Many professional go through a period called as a 7-year itch (started with married life after 7 yrs). This is a period of heightened dissatisfaction professionally and lasts for 2-3 yrs. You are a little early for a midlife crisis but at the right age for difficulties around 30.
For various reasons like settling down, starting a family, new responsibilities, the reality of the job sinking in that's often different from what we dreamt about can cause one to feel 'under the weather' in our mid-thirties.
Trust and accept yourself and your skill sets, Stop comparing yourself to your contemporaries and stop caring for the adverse comments passed by such people. You are what you are and if you been there for 7 years means that you do have the essential requirements to be the retail branch manager.
What you need is a critical and threadbare assessment of what you have in hand, what you need and how realistic are your chances of getting that dream break.The last thing you need now is some hasty decisions. Have a short weekend break, enjoy the solitude, attempt to find your inner self and come back re-charged.
Have an honest discussion with a good friend, senior from the same branch or a different branch or brand whom you know and start analysing your strengths and areas for improvement. This may take a few days, spend time bonding emotionally with siblings, spouse or children depending on your family situation.
One you focus on positive thoughts and good things around you, then go back to the chart of your skill set and the areas you can improve on. If you find that taking a part-time course or focussing on a less known aspect of retail banking can improve your knowledge and skills, then move on to the next step of developing a framework. This framework will have the targeted time,finance and resources needed for developing yourself.
Start this while you continue your present job and meet your supervisor or boss for the promotion or a new addition of responsibility that you lead to a pay hike. If your current employer can't meet your expectations, then start looking for the next best competitor in your retail banking sector at your place or a new place. Often people change their jobs for the next higher title, move to further branches in smaller cities or towns (eg Branch manager to Regional head) and then come back to the city in a couple of years at a higher designation.