Hey man, actual Mech-E here. Also general mechanical hobbyist and handyman; not just one of those CAD guys

Just some quick things that may help you point you in the right direction. This is coming the "small scale hobbyist", not indusdrual profesional viewpoint:

-getting better and making actual projects come to fruition is actually a lot like CS. A lot. Somebody can spend all their time reading CS theory, textbooks, MITOWC, whatever. Their technical foundation will be strong, but will struggle when it comes to coding syntax and spesific program/firmware issues. Some get stuck in that mode and are paralyzed to take action

I'd honestly recommend dropping the mech-E textbooks to read just for reading's sake. It will fill you with generic knowledge but not a better builder. Instead I'd be thinking about "what do I want to build"? Kitchen knives? Custom pens? Automotive mods? It does not need to be something you make forever. Just something that seems fun now (just like the pet CS video game project)

Just like CS hacking (in the PG sense), THEN you will start to look up how it's done. Kitchen knives need metal forging? Okay, now its time to look up edu material for that. What tools are needed? Can I custom-make tools to get them cheaper? What edu material is out there for that… rinse and repeat

...just remember 2 things. 1, safety first. 2, a pretty drawing means nothing if you can't manufacture it to your desired specs

-honestly, drafting or 3D modelling, it's all fine. What's important is what allows you to implement your ideas and record them fastest. Also, right tools for the right job

I made a bench for my balcony. Just rough, imprecise measurements, knowing I'd make ad-hoc cuts to size when I had my material

For extreme lightweighted, funtion-over-form stuff or geometrically sensitive stuff, ya, CAD or FEA software will be needed

Just use whatever is appropriate and will allow you to achieve the results you want. Honestly, if you're not making F1 parts, drafting or CAD is fine

-your proto-prototyping is GREAT. This is exactly how you get started into this. Try something out on a small scale, see where you could improve with tooling, materials, methods and process, try again. Want to make a bronze casting? Try plaster casting first. You say you're lost, but you are ahead of 99% of people in all the damn makerspaces or home hobbyists. Trust me :)

-janky tools. Beautiful. For things that don't need to hit specifications (like firm +/- tolerances), this is one of my favourite things to do. I made an air extraction unit with a thrift shop electric leaf blower motor and some scrap hvac conduit. This is a crucially important skill IMO, as mechanical things get expensive. This allows you to go MUCH further with the money invested to try things out

-collecting weird stuff? Get some plastic bins. Lol. Out of sight out of mind

And last tip? When things around you break, try to fix them. That really starts to add to your "mechanical intuition". I'm pretty familiar with hvac, plumbing, general indusdrial fastners, air and fluid power systems. Next time your sink clogs up, don't call the plumber right off the bat. Explore tutorial videos to see if you would be comfortable doing it (and no problem of you're not; i am not with electronics). But at least you start to get very familiar with standard tools, parts, designs, etc. It's almost uncanny how similar many product classes are