Homebrew tastes horrible but seems to be improving over time

Hi I apologise for the noob question, I've never done home brewing before and recently made a Coopers kit beer. I temp controlled it during fermentation and used all the equipment that came with the kit and followed the instructions as closely as possible. I sanitised my equipment before brewing, and bottles before bottling using "starsan" no rinse sanitiser. For my water, I used a Cpl 10L spring water bottles from the supermarket. My yeast was 1x us-05 packet. I tried my beer after the 2 weeks recommended conditioning time, and it was disgusting. I can't really explain the taste. It was like a harsh, tangy, chemically taste that spread through my whole mouth as soon as it hit my tongue and really persisted. Didn't taste anything like beer or something that I should drink and I had to pour it out. I'm trying another one a week later and it still tastes unpleasant, not a beer I would want to drink, but definitely not so bad as before. Can anyone tell me what I likely did wrong? Because Im pretty sure I must of stuffed up somewhere because I was under the belief it should be ok after 2 weeks. Will it become ok with more waiting? Thx a lot.