How can I bridge my confidence gap to put myself out there more and ask for help more aggressively?

• If you're asking high-quality questions in more public settings, you are actually creating value for your team and the org overall. This is one of the beautiful things about asking for help: It has a pretty high impact ceiling, and if done properly, acts as a force multiplier, which is the kind of behavior I would expect from a senior+ engineer.
• If you get really amazing answers and you feel like your Q&A pair is broadly applicable, consider eternalizing it into a more permanent/central place like an onboarding wiki. That's true impact!
• When it comes to behaviors like these, make it your mentality to overshoot. Since you have this natural limiter, trying to incrementally improve your behavior doesn't work too well: It will take too long for you to get where you need to be. Your goal should be to ask so many questions that people tell you to stop. This scenario will almost certainly not happen as long as you keep the core question-asking principles in mind (which you already seem to have!).
• In general, when it comes to building up positive behaviors where you have some anxiety, make it your goal to leap to the positive extreme. This will balance out with your anxiety to create the desired outcome.

Related resources:

• Asking Effective Questions That Get Great Answers Quickly
• Make It Easy For You To Receive Help