Just got back with ex and think I have STD

Ughhhhhh. So, my long term boyfriend and I broke up in April. I had a really tough few months following the break up with depression which was a lot to overcome.

5ish weeks ago ago I was on a night out, had too much to drink and had a very regrettable one night stand for the first time in my life. Afterwards I had a UTI then thrush both which cleared up. 2 weeks from the one night stand I went to get checked because I got myself so worried I had an STD.

My test results all came back negative. I still had slight itching but nothing concerning.

So roughly 2 weeks ago my ex from April and I reconnected after realising we didn’t want to be apart. We got back together and slept together last week and everything was fine....

Until at the weekend there I got heavy yellow discharge with no odour and a slightly sore vagina and the itching returned. Today I went back to the clinic and got checked again because apparently the last time was the “window” period meaning infection might not have shown yet.

I’m so upset and angry at myself that I could have an STD and have now passed it on to my boyfriend. I’m so scared because I can’t lose him again and feel like he’ll leave me over it and think I’ve either lied about being tested the last time or slept with someone else since which of course is not the case 😥

Would really appreciate some advise or positive energy my way lol got myself so stressed out :(