I actually just got back a few weeks ago from my third solo trip (I've done a 10 day, 9 day and a 6 day on this last one). Unfortunately, I don't have family or friends that understand my love for Disney so I don't have a choice really who goes with me. I am also kind of introverted (okay super introverted), but honestly I have a blast when I am down there. Try going solo! It is a FANTASTIC way to experience WDW
I do get the occasional stare (even that is an overstatement though), but that is probably because I am a 28yo dude wandering around on my own (especially hilarious when I get the urge to ride Goofy's or Pooh or Dumbo or have a romantic dinner for one at Jikos or Artist Point
). My first trip (took 2 years worth of courage to book it) was one big panic attack as I thought every single person was looking at/judging me until about 3 days in when I remember sitting on Main Street with an ice cream feeling sorry for myself (can you get any lower? haha) when I simply perked up and decided I honestly didn't care what people thought. I say "Let them look! Let them make judgments! Nothing they say or think is going to make me want to leave WDW early or never come again. They are entitled to an opinion but I don't have to agree with it. I'm going to have some FUN!" Just remember that there are tens of thousands of people in the park with you and maybe you get a handful of looks, but how many will you ever see again? None! So who cares! Understanding that made that trip and the next two sooooo much more enjoyable!
Yes there are times on rides or at meals when you want to share the magic with your friends, but I quickly dismiss it with the fact that I can/should also enjoy the moment for myself (not to mention the fact that there's not much you can do in those situations except to maybe text/call/snap chat a friend?). Like Dodo said, you have to be comfortable with you and being alone (even then you can call a friend, chat with a CM or be sociable with people next to you in line or at a meal); so if you're cool with that then there shouldn't be a reason not to try going solo.
As for the hotel, I am in there for as little time as possible; I stay at the Values (b/c there is no reason to pay for a room you don't spend time in). I like photography so I am generally the last person in the park every night (best feeling in the world, by the way), plus it is a great way to "distract" yourself throughout the day (some people play on their phone, others bring a book, I like taking pics. Bring a "distraction" just in case). But if I do get done early, I resort hop or find a bar I haven't been to before to hit up and then by the time I get back home I am ready to upload pics and then go straight to bed. Sitting in the room by yourself for several hours would be a drag (and a terrible waste of time and money); find ways to occupy those minutes, even if it is just sitting in a chair by the pool with your phone. Keeping yourself busy is a good way to distract you from negative thoughts/feelings.
Sorry I kept going on and on. I just would hate for you to miss out the way I missed out for so long. I think it might be my "calling" on the boards to encourage solo travelers to give it a shot