ok so as a fellow person who's typically a bottom fragger here's what i would suggest.

1) play a lot more pubs and deathmatch, i would suggest nbk server since they play similar maps to wl pugs and you can practice learning callouts on each map, where the effective areas are to flash/smoke, etc plus you get 16k so you can practice with whatever weapon you want. its generally expected that you'll know basic parts of gameplay like where to aim and strafing so i wouldn't really expect people to tell you about that and it seems you already know to do that stuff anyway.
2) dont use utility unless you know what you're doing with it, i.e., dont get fancy with flashes and smokes. i don't throw em unless i know where they're going
3) i've made this mistake before and i feel really bad about it (sorry junior, i forgot that i was an adult and i was having a terrible day IRL) but really try not to be so defensive in game. i know everyone has said this but its totally true. if things are getting rough just talk about the game and move on. you don't have to try and defend yourself every time someone says something to you. just gotta let it roll off your back. i think that's why people are getting upset, because they think you don't know that you did something wrong or something that didn't make sense
4) have a short memory every time you fuck up, that's what my coaches told me when i played football and it applies here as well
5) don't call out unless you're 100% sure that's where the opposing players are, like if you see something happening. if you don't know whats happening say you don't know where you got killed from or whatever. this is especially valid for maps you don't know as well
6) ur gonna get pooped on from time to time, its really not that big of a deal when it happens.
7) i would say that i bottom frag in about 2/3 of pubs i play and ive kind of learned to accept that. so what i do is i try to entry (and die first w/ info) or carry bomb so i can get plants on T side, and then play a spot that i'm comfortable with on CT side.
8) do stuff that makes sense and will help your team, don't try to get cute with lurks or long rotations

im not sure if people dread playing with me on their team and i hope they don't (and if you do please tell me, i'm a grown man and i can handle it) but i think this is at least why people don't scream at me for reasons other than i'm not fragging. good players don't mind carrying as long as you're helping them win. if they're carrying you and your team is losing of course they're gonna get frustrated and probably take it out on you but you can do stuff other than fragging to help your team out