Can someone give me some tips on climbing?

I've been on a back and fourth spiral of being b2 to b3 to b4 then back to b3 and now back in b4 once again. I know in some of my matches my cs could've been better but sometimes I can't just sit in lane and farm when my team is fighting in jungle. I've been trying really hard to get out of bronze but no matter what I do it feels impossible. My most recent game I lost because my team has no map awareness and can't back with me when someone is split pushing even when I ping it multiple times. I'm this close to buying a new account at this point and seeing what happens. I see the same mistakes in my team: 1. Pushing lanes hard with no vision on the enemy team (especially squishy adc's), 2. general not knowing how to farm under tower or build correctly (for instance I had a support lulu building eye of the watchers and dmg when we were getting shredded), 3. I ping mia and danger multiple times and they think oh no the mid laner wont come to my lane heheh lets keep going and feed them , and lastly, 4. tHROWING OUR LEAD. In what world does it make sense to be an adc with 11 kills and going into the enemy a 1v4 like they don't have 1400 hp and then turning their 2 deaths to 9 just to maybe get a kill??? Anyway, would love some tips and advice and possibly a couch.