1992 Saturn SL2 My car won't stay running

Hi. I am needing answers about my Saturn. For some time, it would run fine and, eventually, it started dying on me sometimes when I would stop at a light or wherever. Then, it would just start sputtering. Often it would run fine when it hadn't been started for a short period of time. Then, it got harder and harder to get going. Once I would get it going for a period of time it ran ok. But then, it was hard to keep it going and then start again. The battery never seemed to be weak unless I had tried for an extended period to start it. Now, it will not start at all. For a while, it seemed that gas line antifreeze would work once it got into the system. Now, nothing seems to get it going. We contemplated the idea that maybe, for some reason, the gas gauge was incorrect. Now, since it isn't starting at all, we aren't entertaining that idea anymore. I have wondered, since it seems to sometimes backfire when trying to keep it running and it doesn't seem to be getting the correct rhythm to stay running, if there may be a timing or spark plug issue. I am wondering if it is firing correctly. Maybe the spark plugs need changed or regauged. The problem is that I am just a woman and the men who are looking at it are just not giving any credence to my suspicions. Could I be right in your professional opinion? I do know some things about cars and am frustrated that no one will llisten to me. I also have really good instincts usually. Because of what it is doing and the way that it sounds, I am convinced that these things should, at least, be checked. We also found a vacuum line that didn't seem to have any place to go. We are not sure why or if this is part of the problem. What do you think?