All the best trips I've ever taken have been alone. As said earlier, if you are unable to take mushrooms without a babysitter to prevent you from doing something stupid or dangerous, then you have absolutely NO place taking any form of hallucinogenic substance. You simply lack the maturity to properly dose yourself, or you lack the mental fortitude to face a deep, true introspective experience.
That said, do lots of research (if you've never been there, go to
Shroomery - Magic Mushrooms (Shrooms) Demystified - They are to mushrooms what RIU is to herb.) Understand the potential effects and honestly evaluate yourself whether you are comfortable enough with who you are to really face the potential worst of what your mind contains. And most importantly, START SMALL!! 1-1.5 gram is fine and probably ideal for a first trip. It will not explode your mind, but will give you a good sense of what you are in for and how you can deal with it. As you get experience with the substance, increase your dose and really get ready to see some things about who you are.
Mushrooms will not make you crazy, they won't fry your brain or give you schizophrenia. If you have a bad trip (and you will, at some point, if you continue to trip, understand this above all) it willl suck. It will scare you, it will make you very uncomfortable, and it will be a shit night for you. But it will end, and you will either be strengthened by it, or you will allow it to cripple you, and that is when you will really see what kind of person you are.
If you have doubt about the trip or yourself, don't do it I say. Mushrooms are an extremely powerful organism, and just like you don't give the keys of a 20,000 pound diesel truck to a 16 year old, you can not expect anything but disaster from allowing an unprepared mind access to something so significant. If you are ready for the experience, well you don't need me or anyone else to tell you what to do. You already know the mushroom, you know the significance of the experience that you are about to undertake, and you are prepared to accept the consequences of what you find in there, no matter how awful it may be.