Honey, not saying anything because you're afraid to damage the relationship is the worst thing you could possibly do. That's how people end up being abused.
Because they don't want to do damage, they want to let it slip, they except it to only be temporary. Love, friendship, family, doesn't matter. When it comes to that it's all the same.
You need to tell him he's going too far. Maybe he's getting carried away, maybe he doesn't notice it. Maybe he's testing you. You can't know that unless to call him out on it. Either way, letting it happen is not healthy, if you're regularly being hurt or uncomfortable, the relatioship is already damaged anyway.
I used to have really bad acne too. Every morning and every time i shower i rub my face with clear water, after washing my hands, bare hands, no soap on the face. it's getting better, now i only have someon my cheeks and occasionally a few pimples around the lips.
As for weight loss, just know it's a common thing to see yourself as bigger than you actually are and muscle being heavier than fat, if you exercise, you'll feel like you're not making any progress if you pay too much attention to the scale. Because you loose fat but your weight is stagnant.
Drinking a lot of water helps.
So, you're bi leaning towards men. So far. I think you should take a break. Trust me, she may not say anything right now but when someone isn't happy in a relationship with you, you eventually start to feel it. If you stay in a relationship while wanting something else you're only gonna end up making both of you feel bad.
Of course she probably won't take it well but in the end it's better to be honest about it and maybe figure this out, possibly finding out you're gay rather than staying on a "maybe".
Whatever you chose, good luck with it!
Everyone makes mistakes, it's okay, just don't panic, It's normal to be anxious about this but it might be nothing, really, porn sites are full of various malwares and viruses. Avoid porn sites for a moment and keep doing what you usually do. Don't clean your browser history out, IF (i insist on the IF) you ever get controlled, it will make it easier for your device to be checked for anything weird if the history is still there and also easier to find what could have caused the issue.
Remember that you really have nothing to hide and you did nothing wrong. This kind of thing happens all the time on the internet. You'll be okay.