To prevent editing, multi-posting and drug induced gibberish, people are encouraged to not post during their trip but keep notes and then once sobered up post a clear and concise trip report of their experience.
Also Diphenhydramine is a deliriant which can cause very intense and generally not exactly "enjoyable" trips. I would definitely advise against taking it as a first time high and there is no way I would go near it.
edit: I see you already took 300mg so just have fun and enjoy it :D