Gabriel Knight is a hard adventure game. It's also unforgiving. Perhaps you should try lighter games (you said you enjoyed Monkey Island)?
Besides, a lot of people like difficult puzzles, because when you finally solve them, you feel very satisfied. If you don't enjoy this, however, don't feel ashamed to use a walkthrough. I don't see any harm at that. For some of the games I finished I used a walkthrough from beginning to end, because I didn't want to spend too much time on them. Can't say I didn't enjoy just because I used a walkthrough.
Now, you're saying you're not an adventure gamer, but you have one quality which I consider a must for any true adventure gamer - you don't consider Myst an adventure
you really do understand the concept, then.
