Cheating husband and yellow discharge

So I woke up in the middle of the night last night and I went on my husbands phone to send some pictures to myself from the day before of our vacation and I went on snap and saw something weird so I looked more and found out he was flirting with a girl and one of the messages from the girl said “In bed. Wanna join?” And he replied with yes. So I looked some more and found out he was getting off and chatting with at the same time to live girls on Instagram from states away. I’m just so hurt and surprised. He literally kept lying to me the entire time but I had proof to call him out. He literally said she was depressed and was trying to boost her ego.

Now...

I’ve had yellow discharge every time I wipe and I thought it might be normal from looking online since that’s the only symptom but I’m wondering if he gave me an std.. I’m going to try to get tested tomorrow but I’m freaking out with the what if’s and how I’d confront him.

Pls help or help calm me down.