Then maybe you need to flat out tell him that you are his business partner and that you will not tolerate him talking to you like that any longer. Start to draw up your boundaries.
"and so to continue with our day, h got further irate with me when he felt that I was trying to take the rest of the day off, when he felt that the day was far from ending for him."
Ignore this. It's his way of not being able to deal with the stress in a healthy manner. Tell him you're sorry that he feels overwhelmed and that you are more than happy to help him, HOWEVER that you will not be the scapegoat to let his frustrations out on.
"He didn't see it as me offering to help. Then we got into the money again and he got pissed off that I "again" didn't bring the petty cash that he needed to pay off some people."
Then walk away.
"His voice escalated and then mine did too."
You have to learn to walk away before it gets to that point.
"I quickly said that if he is going to yell at me then I was leaving and he could call me when he could speak better. I then threw our business keys onto the ground and began to pull away. I stopped and thought this isn't how I want this to go. So grabbed the keys and walked to his car. He continued to yell for throwing the keys."
Then I would have dropped the keys where you were standing and walked away.
"I said that he wasn't seeing my point."
No sense arguing that point.
"He was now getting more mad and was in a hurry. I said I would get him the petty cash & meet him back at the house."
You shouldn't have done this. Let him get it himself.
"I called on the phone to validate that he is having a meltdown and I was getting in his way. He corrected me and said not a melt down, that he was overwhelmed."
See? You mindread him wrong.
"I then texted him "I don't mean to get in your way. Im only trying to help. It doesn't come across as that, and it seems to bother you more" He didn't reply."
Of course not because you're still mindreading. You don't need to constantly explain yourself.
"When I got back to the house with the petty cash. I tried to explain that he just takes the money & doesn't explain it. (meaning I was wanting to discuss how it was being spent)"
No sense explaining this point AGAIN until things have cooled down. YOU NEED TO LEARN PATIENCE.
"Again, he was in a hurry."
He was doing it to blow you off.
"Didn't say much. I said that I am trying to help and wanted to be outside or helping with driving, etc. He said then go to the lot (his) and do something there. So ... I did."
You should have just left.
"IF/when he texts back to "appreciate" what I did (manual weeding), I will text back to say "I understand you are overwhelmed, I am just helping""
You really need to stop thinking that you always have to say something. We've told you time and time again that you have to just let him be. No response is necessary. Plus you're going to get yourself disappointed if he doesn't text you with an "appreciation".
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.