First, I wanna apologize for the long post, but it's my first post on this website ever, and I just felt the need to write this all out because I feel like I was in a similar situation as you, with coke and other drugs at one point in my life.
I too grew up in a family environment that was very anti-drugs, however, the older I became the more I, along with many other people I assume, began separating drugs into groups, which were typically based on how "bad" or "hard" they were. Now obviously meth and coke are both "harder" drugs than weed, everyone knows that, but I think that this separation of drugs into groups is what started me out into exploring them. Alcohol was something I tried at a young age, and by high school I was smoking weed, both of which I was initially afraid to try or do because of all of the negative things associated with them, mostly weed at the time. So my reason for saying all of this is that I can remember in high school, before smoking weed, that I was never going to, but then I became interested because others did it, and I soon did it myself as it didn't seem that "bad", and it certainly was nowhere near as "bad" as cocaine is, so I felt justified in a way, like I could be doing "harder" drugs and really be fucking up. So after experiencing weed and loving it in college, I used to always say I would never do coke, or meth, or heroin. But then I discovered adderall, which I think colleges in the past few decades have done a fantastic job of unintentionally introducing college kids to it, and my life changed. I took it and felt like superman, then over the course of purchasing it from a friend for two years, I finally got my own prescription, and even did my senior research project on the mechanism of action of adderall in the brain. Long story short, I tried coke for the first time after having taken adderall for nearly 3 years, not everyday, but pretty close, and I only decided to actually do coke when I would be out of adderall. So I did coke, and honestly I think it's a waste of money, now I don't know how pure the coke that I received actually was, but I'd say it was pretty decent, and my biggest issue with coke is that you get the same feeling from coke that adderall gives you, but it only last for like an hour and it's waaaaay more expensive. Now, like I mentioned, it could have been terrible coke, it's possible, but why I think I don't like it is because of my super high tolerance for pharm-grade amphetamines, and my love for adderall. But to answer your first question, yes, I have felt the guilt you're talking about before, as I know many, many others have, but the level at which the guilt effects you is determined by how guilty you make yourself feel. What I'm saying is, if you've done drugs before, any drugs, you've done it because you were curious or wanted to feel something that you're lacking, and that's fine. I feel that if you, in your own mind, weigh the pros and the cons, and the pros win, then try it. It's just ultimately up to you to control that use of the drug, whatever it may be, and to not allow yourself to make yourself feel bad for doing it. Also, when I did coke, the actual act of snorting the cocaine wasn't what made me feel guilty, however, it was during the drives I would make to the seller to buy it that I would feel the most guilt, because I was consciously bringing myself to go obtain a drug that I once felt so opposed about ever doing. But once you get over that aspect of it, the mental part, you'll be fine. Oh, and last thing, I guess I'm also saying that there are better drugs out there, so if you really want to experience a speedy high, try and get your hands on some addys.