People seem to develop some sort of confusion in their mind trying not to do certain things under the banner of self respect and ego. What are these words? Can these words be interchanged and used? Do you really need someone well versed in the field of English language or perhaps a psychologist to explain this to you? No, you don't.
Ego, often considered to be a negative aspect, is a tag given by people to a person as they feel he/she doesn't voluntarily do something in the first place. It arises within a person when he/she doesn't feel the need to connect with a person voluntarily and always waits for the other person to start the chain of conversation. It might arise out of jealousy or out of the need to check if the other party is genuinely interested to have a conversation with him/her.
Now, one is prone to get confused between ego and self respect. Lets take an example and make this explanation simpler. Imagine a person who is genuinely interested to provide help to people to make them lead a better life. Lets say that on a daily basis, he supplies goods to people who need it to perform certain activities. Now, if this person suddenly starts feeling as to why should I be the one who should help them when I am getting nothing in return everyday and then decides not to supply anything unless he gets what he expects, then that person can be tagged as someone who possesses an emotion called ego.
Now, if the same altruistic person keeps doing good deeds without expecting anything in return, but if the people who receive his goods on a daily basis start accusing him of not providing enough to them and that they would be better off without his help and start speaking low of his work, then in that case, if the person stops supplying the people what they need as he feels that his work, instead of being appreciated has been taken for granted, then self respect is an immensely important factor of our mind that tells us to step away when treated any less than what you deserve.
Ego is what makes you destroy relationships and takes you a step down from being a fantastic person in life and self respect on the other hand is that part of your mind that tells you not to climb another step and back out from the negativity and makes you feel stronger from your heart and mind.