> I know I should just pick one and stick to it, but its very hard.
You already know the answer. It is hard, but only because sticking with something means making a choice, investing time, and taking accountability to learn and do something with your new skillset.
> I have a lot of ideas I want to build/prototype quickly, but every time starting a project I feel stuck and paralyzed with many choices, end up reading internet and HN for 3 days on all possible tech choices and find myself tired even before starting project.
A few things. You mention you want to build/prototype quickly, but the tech stacks you mention aren't really rapid development environments. You might be getting frustrated because you're playing in objective-c when you should be on a whiteboard working out an idea.
The situation you describe isn't easy to get out of until you address whatever fear is causing you to over-worry about every step.
Overthinking is an escape. As you're learning, it leads nowhere. You will have to break this cycle by actually creating something and making a choice and sticking with it.
The comfort of knowing what you're doing the way you feel with obj-c is likely years, not days, away in any new language. If you actually want to feel like a deep expert in something, go back to what you know and freshen up. Anything else needs more than "3 days reading HN" level of devotion and energy. There's no shame in not having the energy, interest, or whatever, to learn something brand new.
I generally think people who are in this mindset of feeling paralyzed when they're fully equipped to succeed need a real wake up call.
Be honest with yourself about what your day looks like: how many hours are you spending in your head or looking at a screen vs. in the world interacting with your community?
I am just guessing, but based on reading this, you probably need to immediately change up your routine to get out of this rut of thinking or you will wake up old with every opportunity behind you and no chance to take it.