My Ethical Egoism Theory

Which of the various theories of morality is the closet I believe? I believe in my opinion. The most I believed must be ethical egoism. According to the definition the meaning of ethical egoism. Is based on someone best interest, which claims that individuals and myself only act in our self interest in life. For example, there was one occasion when I was following a powerlifting program and I was getting teach someone, who had experience powerlifting for almost 15 years of training powerlifting. His name was Vadym Dovhanyuk, he was my mentor, he was my source of knowledge of his workout ethics. When Vadym Doyhanyuk believed of me that one day I will be a champion like him. I laugh and thought of him, just being sarcastic. However, why I choose this theory ethical egoism, because it was my self-interest to use my money from out of my pocket and all the saving I was wasting and I know. I could use that money for essentials thing, and during this journey for almost 8 months of training I saw progress in me and he saw progress in me to. Vadym Doyhanyuk was trying his best to teach me all his workout ethics
and he also apply the ethical egoism in his way, by trying to lower the price because he always tells me that. he sees a potential powerlifter in the near future for competing a powerlifting competition. I was only 19 years old when I met him and I told him my total number and he was impressed for my age lifting heavy, so he told me for our interest he lower the price down because I ask him, if he could reduce the price he said yes, due to our best interest. For instinct, he always loves teaching me his workout ethics, and he was passionate about this to get me stronger, and he believed me, when I didn’t believe myself. He loves doing this, so was I no matter the circumstances were. However, another theory I believed was utilitarianism I think is very important for me what best for other, no matter what is the circumstances we are in.
When my grandfather got really sick at the point. The doctor said he has at least two months to live. Luckily the doctor was mistaken, for now my grandpa is feeling better, I always help my family no matter what for the best for my grandmother and my mom, they always there every day helping my grandpa. However, after school or after work I go downstairs and help them with my grandpa, so my mom and grandmother could take a break and help around. Yes, I do have a blending theory, is altruism is a metaphor for utilitarianism both of the theory applies the greater good for the people meaning by the best interest for everyone. Like I said I did for the best interest for my family to help out with my
grandpa.