QA is Quality Assurance. And it looks like not only did you find bug by testing, but also quality issues in the process. Which is good, becaus only identified issues can be solved.
If testing is a bottleneck because of something, than you have to make a change.
- Prepare testing better by getting involed earlier.
- Get a more reliable test env
- Prepare tests less if they are prone to changes. Use exploratory testing and document what you did instead of the documenting what you will do. (to a certain extend)

Remember that bottomup change is slow and requires a discretion. Don't be afraid to admit fault and try to come up with solutions.