It is unfortunate that your friend didn't keep his word and give you back your money in time, otherwise you would've won more than just 50$˜.
But it is a lesson for you so next time you will be more ready to gamble with the right amount of money and have the opportunity to win more from your betting. Meanwhile, you shouldn't feel bad because at least you earned that bet which is very impressive.
I see that you have the skills and vision in sport betting and I believe that you are going to face more and better opportunities in the future but just make sure to be ready and have the right amount for betting to not miss such big chances and win bigger.
I also think the same, here the most important thing is what has been learned, there is no other way, with this type of things a player gains more Experience in what he Should and should not do, for that reason we will always be generating more skills. things are fine, in a casino one can make mistakes, it is something very normal and sometimes things don't go as desired , but Mainly what is learned is what will make us earn more money when a situation arises. Similarly, you already know how it should be done, in this sense each of us Knows what moves should be made, that things are always better done with our own money, in any case always that we are with a magic , or friends, let our juice always be for us, when we do something between two or for another person, then it is done with as much restraint as possible, this can avoid many things.
This also reminds me of a thread where it was said that with every gain or every loss, you have to tell your partner when you were making a movie or something, but always when things are done with partners and with other hands, it is not good to do it like that, because basically things always end in fights, in misunderstandings and that is what should be avoided the most, for us not to fall into these things it is always good to have and do our things in the casinos, alone, without lending money or doing something trivial , not only to avoid what happened to OP, but also to go through situations that are unpleasant for everyone, this is what we must draw as a conclusion so that no more situations like these happen, now that OP stopped liking it, it was something which I do not understand well, because he would have taken more risks, but since he is in control of his actions, I will always think that when it comes to ownership things are delicate , obviously he is always delicate with money, any situation he takes can happen for the good of one as a player.