During my early days in the crypto industry, I had upto $158 in my wallet balance, I was told to buy only Bitcoin by the guy mentoring me, which I agreed to it, a few days later, a friend of mine told me that their is not much profit from Bitcoin, so he suggested a coin to me called Gft, I ignored the advice of my mentor and go with that of my friends.
I bought that gft at a price of $0.1100 with all my usdt, it was not even up to a week, when the price of that token fell to $0.6000, and my capital of $158 was not even up to $80 again, after upto 7 weeks, it was still coming down, I just have to cut my lost, and sold all the coin at $74, right now that coin is trading at $0.0230, after then, I learn my lesson the hard way, I never told the guy mentoring me, because I know that he would be really mad at me, since then, I stay off any coin that is not Bitcoin.
Mate am happy that you have learn and I believe that you are not going to make such mistake again, though is normal for you to blame yourself in this situation because you refused to listen to your mentors advice as you said, the problem many of us are having as bitcoiners is greed and lack of patience, this usually happens to people that does not understand bitcoin, though most times is not easy to take some decisions, that's why is advisable to make a good research about bitcoin and it's activities, despite that it is almost impossible to predict bitcoin movement because of it's volatile nature investing in it is more efficient and trusted more than other coin, mate you should forget about the mistake though it will keep reoccurring to you, just concentrate on your future in bitcoin and make it right as time goes on, this is my take on this.