Are situations at your current place of work causing you to consider a new career?
There may be appraisal systems, grievance procedures or union representation in your organisation, all of which might help to resolve the issues. Regardless of the outcome, you may still wish to leave your job. If your employer is a major player in your profession or the practices that you dislike are endemic in the profession and not just in the company where you work, you may feel that a complete change of career is the best option. This must be considered carefully.
If you do leave your job, remember that it is better (if possible) to leave with a new job arranged to avoid a period of unemployment.
Try to organise a general reference / testimonial from your employer.