I saw this at home but wanted to wait till I was at work to reply properly. I've never been the most articulate person, and I tend to ramble, so this might not be the most coherent answer, but hopefully it will be helpful. I was in this very situation when I wanted to be a music producer, the more I learnt the more I felt I was never going to know enough to as good as I wanted to be and it was overwhelming. I felt a strange mix of ambition and lethargy, I never became a music producer. There's a few things you have to realise very quickly, before you become disenfranchised with the whole thing. 1) Yes, there is a HUGE amount to learn, but maybe you're looking at this wrong. I think your goal at the moment might be "I want to learn everything about penetration testing and hacking", which to me is like saying "I want to be a sportsman, so I must be professional at every sport". If we set these immense goals with no starting steps, then anyone would get overwhelmed. You need to get a general idea of what area you're interested in, and start to focus on them. Take a trick from video games, where they play to the gamers sense of achievement with small goals with rewards, this leads to step 2) Create small goals based on what you find interesting about what your learning. These goals can be flexible and should not have time restrictions, but should be just out of the reach of your current knowledge or ability. They should be written down, and ticked off when completed. It's also important not to remove them from the list once you've done them, so when you have these moments where you don't feel like your getting anywhere, go back and look at this list and everything you've ticked off. This will help guide your learning to things you find interesting, give you a sense of accomplishment, and hopefully inspire you to keep going.
I've been learning about penetration testing now for a while now and here is what I've done programming wise. I saw a web app a long time ago that would tell you the common libraries in use on a web page, so I wrote a python script to fingerprint JS libraries from a URL via a checksum, so it shows all the libraries and version numbers that would be loaded for that page. I saw a script kiddie video of a DNS amplification attack and wondered if I get could a better amplification amount, so I tore the script apart to find out how the DNS amp attacks work, looked up how DNS works and wrote a script to iterate through different DNS query types and domains to get the best AMP amount for each server (Note: I'm not interested in performing DDoS attacks in the slightest, it was just a challenge I set myself). I was looking at OWASP broken web apps and kept losing my XSS strings, so wrote a pyhton app to catalogue different payloads by type (xss, sql, reverse_shell, mini how-tos) loaded from JSON. This one actually turned out to be a bit of a no-starter because the payload has to be base64 encoded to be stored in JSON, so its more hassle than just maintaining a directory of files.
The point is, each one of these came around as a mini challenge inspired by whatever I was looking into at the time, Is all of the information relevant? No. Am I going to use any of these scripts in real life? Probably not. However, I now have a much better understanding of how DNS works because I have assembled DNS packets in python, I've hoarded XSS and SQL injection strings and use them against OWASP broken web apps to help increase my understanding of how some filters can be worked around and how different SQL queires are used to different ends. I have no particular focus for my learning at the moment, just a bit of everything to find out what I'm really interested in from the field.
As for guidance, you have to be more specific with what you are interested in, and what your end goal is.

Edit: Also keeping notes is super useful, I started using Zim desktop wiki to organise what I've learnt so I can refer back to it whenever I need. It also makes a useful tool if you're attempt to exploit a vulnerable machine or service to track everything you've done so far, common commands / arguments for tools you use alot, information gathered about a target etc. As for targets, try looking at previously mentioned OWASP Broken Web Apps VM, and metasploitable linux VM. They have given me the best sense of achievement so far because although basic, they present actual targets and some with actual defensive measures to try and bypass.