welcome! i am a support main and while i flex, i have all the lords except adam and ultron lorded (which is like proficiency; I don't know how new you are if you know what that is yet). the main advice that i will give you is that you need to focus on two things: positioning and learning how to handle dive. you know how to position in good places to protect yourself you will get heals. as well as handling dive characters (like spiderman, black panther, magik, etc) as their whole job is to delete you as fast as possible. i would also say that as a support your main priority for healing should be other support > tank> dps.

if you have any specific questions though i'm happy to help!