White foamy discharge only during masturbation.

A little (long winded) back story, I had an extramarital encounter with a woman that consisted of her giving me a short unprotected oral session and about 30 to 45 seconds of her on top of me with her rubbing my penis on her vagina. I know there was a bit of penetration... Not much because I'm not exactly hung. I stopped it because I had a "wtf am I doing" moment and left. I decided not to mention it to my wife since it wasn't full on intercourse and I vowed to never do it again. Around 9 days later I felt a blister inside my bottom lip. I examined it in the mirror and began freaking out. I quickly realized "oh, that's where I accidentally bit my lip a couple days ago (lined up with my front tooth and was the same size/shape). At that point, I realized I didn't know a whole lot about STDs. My wife is my 3rd partner ever and I'm 40... Call this a midlife crisis I guess. I figured I was pretty low risk since "jeeez, it's not like we had sex" boy was I wrong. Pretty much everything can be caught from genital contact except HIV. I got scared as hell and then I began having the frequent urge to urinate like 2 hours after all the googling that lasted the rest of the day, I guess that could be from severe anxiety. I snuck off and got tested for the commons at 2 weeks. All neg. At this point I was consumed with fear, guilt, and anxiety to the point I felt I was going to crack. I came clean and broke her heart. It was horrible but she stayed with me.

I did follow ups at 2 months, 3 months, and 6 months for HIV, gonorrhea, Chlamydia, HSV2, syphilis, (am I missing any?) All negative. Around my 2 month I noticed a white frothy discharge at the tip of my penis mid masturbation. It looked like a bubble of that foamy soap that they have at the Dr office, about the size of a BB. I got it on my finger and examined it... Yeah just a bunch of teeny tiny white bubbles. I smashed it between my fingers to see the elasticity and it just disappeared. "WTF is this??? OMG??? Has it always happened and I never paid it any mind??? Maybe I'm just hyperaware of my body now???". At this point, no other symptoms... Just weird discharge, possibly just weird pre-ejaculate. The Dr said "maybe trich" and gave me metronidazole. No change after that. Did a round of doxy, no change. At my 6 month I requested a trich test. I went to the lab, they gave me a cup and said "start your stream in the toilet then get the middle and finish in toilet". Did that, came back negative. I did more of that fear inducing googling and saw that to get accurate results, you need a uretrhal swab or first void urine. My much needed peace of mind went smooth out the window. At this point I'm too embarrassed to go back so I just chalked it up as normal. Wife has no symptoms so I figured I'm just being hyperaware and making something of nothing. I read that this stuff can be transferred via used towels and loofas which opened up a new door of anxiety... I have a daughter under the age of 8 and I know she's used my wife's loofa and towel from time to time (uhg, children). I tried to drive it in her head to only use her loofa and tell me when she needs a clean towel but stuff like that doesn't stick.

Anyway, fast forward a year. Marriage back on track, white foam still present during masturbation, but I need to move on. All tests neg. I noticed my daughter was urinating alot the other night without taking in Mass fluids. I felt that feeling in my gut but wrote it off. Last night, after she took a shower with my wife, she said her private hurt. That feeling in my gut went to friggin 11. I'm a wreck all over again. If I brought this trash into my house and infected my wife and now my daughter accidentally... Jfc I might not go on living. My daughter is everything to me and knowing I possibly accidentally did this to her would crush me. I know there's other explanations for symptoms like this in girls but I can't get it out of my head. I know I need to suck it up and go get tested again but I'm horrified now of the events that will follow if positive. I'll never forgive myself, I'll probably be investigated by CPS, my marriage will probably go to ****... Everything ruined over one drunken 45 second encounter, yeah that's my crap luck.

My main question is, have any guys had the foamy white non odorous discharge during masturbation? That's the only time I see it. If I squeeze the head after a couple minutes of manipulation there it comes. Never while flaccid. Maybe because I'm older and I'm not producing as much pre-ejaculate so it gets all agitated and bubbles up? I don't know.
Any advice/suggestions/amusing anecdotes about similar experiences would be much appreciated.
I feel like I'm going mad.

Desperate in <geographical location redacted>
Thank you in advance.