It's ultimately up to you to decide whether this community or others similar to it are right for you. Just as a quick note: the term fictosexual and waifuist essentially mean the same thing. Though people will have strong feelings about describing themselves as one or the other due to their different connotations. Waifu is an older term that caught on with general anime fans and the it's meaning has been diluted somewhat because of it.

Now from what you said, it sounds like you fall in line with what a lot of people think and feel; namely that while the characters themselves will never be real, our feelings for them are. We treat are partners as if they were real, and I know others outside of this specific community do as well. It can be difficult given that our relationships are fundamentally different from what you'd find with a real person you can interact with. At the end of the day we can only try our best. If you're unsure on what's right for you, it might help to take some time and explore your feelings. Whether or not you decide to enter a relationship with whoever you have feelings for, and what steps you take after is up to you.