Should I learn zhuyin or pinyin?
I have learned Chinese for a long time, but mostly only speaking and listening

I either just learn by ear, or write it down in English, but I don't use a standard system

I have found charts of different systems and have found my own system either matches some of the various ones, matches but used wrongly, or completely different

For example, 'good bye' is "jhai! jehn!"
Apparently "jhai" is a proper Tongyong Pinyin but does not match 再. "jehn" is just completely my own way
I'm noticing that I'm consistently using "!" as 4th tone though

Another example, 'west' is "hsi"
This time I have used Wade-Giles correctly for 西.

A third example, 'myself is "Zhe ji" with an underline for ji.
This time "Zhe" is a proper Pinyin but does not match 自
I have used all systems correctly for 己 except Wade-Giles and Gwoyeu Romatzyh
I'm also noticing that I'm consistently using underlines for 3rd tone though.

Should I just dump the English and learn Zhuyin or fix the weird English to proper Pinyin???

Question

Should I learn zhuyin or pinyin?
I have learned Chinese for a long time, but mostly only speaking and listening

I either just learn by ear, or write it down in English, but I don't use a standard system

I have found charts of different systems and have found my own system either matches some of the various ones, matches but used wrongly, or completely different

For example,  'good bye' is "jhai! jehn!"
Apparently "jhai" is a proper Tongyong Pinyin but does not match 再. "jehn" is just completely my own way
I'm noticing that I'm consistently using "!" as 4th tone though

Another example, 'west' is "hsi"
This time I have used Wade-Giles correctly for 西.

A third example, 'myself is "Zhe ji" with an underline for ji.
This time "Zhe" is a proper Pinyin but does not match 自
I have used all systems correctly for 己 except Wade-Giles and Gwoyeu Romatzyh
I'm also noticing that I'm consistently using underlines for 3rd tone though.

Should I just dump the English and learn Zhuyin or fix the weird English to proper Pinyin???

Answer

You can survive without learning Pinyin or Chinese Characters, but your ability of  using Chinese  is so limited to  speaking and listening only .You cannot read and write, for example , you cannot learn Chinese on your own, you can't leave a note, etc.
It'd be better if you learn Pinyin.

Answer

If you plan to learn this language very seriously, I personally believe you should pick up the pingyin system. 
Why is that so?

1. The system will make you have access to all kinds of learning material by yourself, even without the assistance from teachers. In short, you can self-study. 
2. Pingyi, comared wiith Zhuyi, is much easier for English native speakers to pick up the system. 
3. Once you get familiar with the rules, you can have a better command of the correct and exact pronunciation.

Cheers,

Answer

I think you should learn Ping Yin first .
We learn English   from the beginning of "A,B,C,D....",and then met phonetic symbol, and included some simple words.
I think your phonetic symbol is similar to our Ping yin in some way.But it is   important to keep them  in your head .somebody sometimes may notes Ping Yin under the word they don't know ,just like you ,prefer to write in your way to the unknown words.
 However ,I had never used this method to learn words ,I will look at the phonetic symbol first how to read it ,and remember the pronunciation,then try to remember the word.

Answer

Pinyin is definitely the more commonly used of the two. Adding on to other answers above, typing chinese characters on a phone or computer is much easier when using pinyin!

Answer

In my view, I recommend you to learn Pinyin. Some people might be afraid that Pinyin will make you focus less on characters. But I think more people are learning Pinyin rather then Zhuyin. 
In mainland China,we only learn Pinyin, many people can't understand zhuyin. If you have some questions. for example, you know how to pronounce a word but you don't know how to write it, if you ask in Pinyin, more people can understand your question and give you more helps. And it is easier and more convenient to type in Pinyin. 
But if your have Chinese teacher who is  Taiwanese, and you are studying Chinese  in Taiwan, you can choose zhuyin.Because they might only use zhuyin, and people who teach you directly can give you the most useful help.