Title says it all.

I'm playing fill only so get ADC from time to time but I'm not an Adc main. I dabbled with it a while back on Ezreal but it's not my best role. Lately I think I'm just getting unlucky but the past three games my sup ditched me and I was useless. In the first game, my sup walked into a naut hook, died, flamed me because he died, told me to "F* off N*" and went afk. Another game, my sup ditched me when I died once and went to "support top" ruining two lanes". In the most recent game, my twitch support kept roaming from minute 5 and leaving me shoved under tower as MF against Cait and Morg for extended periods of time. My 10-min cs was about 45. He also kept trying to 1v1 Cait and dying. I ended lane 0/2/5, both deaths were due to skirmishes in river, (and were to Rammus jgl and Malph top). I ended game 3/8/12 with 130 cs in 30 min ffs and my Twitch was 3/15/13 with 74 cs as he had started to waveclear everything with W and pretty much just denying our own team cs in whatever lane he happened to be in at the time.

Obviously I did not play that perfectly but I'm not sure what to do in that situation other than not feed, don't greed for cs and pray my team carries. The jungle didn't totally ignore my lane, but didn't really gank because normally when he was down botside it resulted in river skirmishes instead (usually for drake), and ofc when I'm in the lane alone he can't do much.

What am I meant to do?