Trading cryptocurrency for a living is currently not for you. First you need to find a job to have a fixed income. Second develop your trading skills or system. Until you are very confident to do trading for a living.
Not currently, the best thing for OP is to never try to trade again! I am not sure that I understand his words correctly, he placed a buy order and that's it?! Money lost? I saw more about his son and food than about trading...
And why would anyone risk everything (in this case $400), on something you never ever tried before?! This is an insane move... and you know you need money for other things, but you decided to go all-in with 0 knowledge about what you are doing... and now the time for crying has come! I don't feel sorry for the guy, I feel sorry for the kid... his dad will make the same mistake again, most likely!
indeed a silly decision, he wants to get a lot of money without any hard work, which only reflects on the success of other people in trading. therefore in everything we have to study it first before participating. what I can suggest at this time is that the OP must immediately make money from his usual job, and do not return to trading before having free money