I think because you're making it to the final rounds of interviews, the decision isn't based on your stutter which is good. Shows that your achievements are showing above your stutter and that you can obviously overcome difficulties. Besides 'keep at it,' have you thought of applying to jobs outside your usual radius? Even areas you'd have to move to? Getting entry level jobs can be rough, especially when most listings say they want 4 plus years experience for an entry level job