Solo Trips are always good to me! My first solo trip I ever done to Disneyworld is still in my memory my best holiday ever.
About getting lonely, it depends just on you....making friends or taking to people in DW is really easy, I always had chances to interact with other guests, sharing experiences on the parks etc.
About activities or meet ups, I cannot help, but I'm sure you won't have any troubles as a solo traveler
I think you can do a solo trip, though it will obviously depend on the individual.
If you align your park days with the red shirt days, it creates a very social atmosphere in the parks. Magic Kingdom day especially. My bf and I talk with plenty of fellow gays in queues or quick service restaurants during the MK day.
The host hotel has pool parties basically all day, every day. Its easy to meet people there. If you are into the constant party scene, you could consider staying at that host hotel as I imagine you would probably make a few trip friends (not a place I could ever stay b/c its loud until about 3am every night with the pool parties. I like going out...but also need to go back to my room and be able to escape that atmosphere lol).
And frankly, apps like Grindr and Scruff have proven great ways to meet people during Gay Days. And no, not just for hookups! I've seen lots of people plan gatherings on them. I'm always finding CMs or locals on there and asking for advice. Scruff also has a "venture" section where you can list a trip you're going on in advance. You could put down Orlando and your dates and be able to converse with Orlando people before you even get there. So you could plan a dinner or park meetup with someone that way too.
I can only use myself as reference, but I think the place I might feel loneliness is doing the rides in the parks. Its fun for me to have a shared experience on the attractions, so I would personally maybe not enjoy doing that alone so much. But that might be different for you.
You will have to decide which "Gay Day@ Disney/One Magical Weekend" or "Gay DayS = the Circuit Party"
If you are a fan of Disney and want to experience the comradery of enjoying your time in the parks, meeting and making new friends, then you want to attend the original "Gay Day@ Disney/One Magical Weekend", which was always held the first weekend in June. For 2019 the core Weekend is Friday, May 31, 2019, thru June 3, 2019. However, you may wish to arrive either Wed night May 29, as Thursday(May 30) is always Animal Kingdom Day, with a large and friendly meet up scheduled around 2 PM.
Sixteen years ago on a solo trip during Gay Day @ Disney / aka "Friendship" weekend, I made several new friends, that I am still in contact with, in fact, we spent time together this past June 2018.
If you do decide to attend the traditional Gay Day @ Disney event May 30 - June 3, 2019, and you are looking to meet fellow Disney fans, then I invite you to keep in contact with me.
I am affiliated with two different groups of friends and we have already confirmed our Host hotel. Some of us will do a split stay starting at Disney's Animal Kingdom Lodge - Jambo House then transferring on Friday or Sat over to the Disney Contemporary. For those looking for a more economical option a few folks with be staying at Pop Century.
THURSDAY -DISNEY'S Animal Kingdom Day
FRIDAY - DISNEY'S Hollywood Studio
SAT - Magic Kingdom - Red Shirt day
Sun - EPCOT
Saturday night there is the amazing dance party held at "House of Blues" located at Pleasure Island/Downtown Disney... ok it is now officially "Disney Springs."
You will find details at "onemagicalweekend_dot_com
If on the other hand, you are only interested in pure circuit parties, that happen to be in the city of Orlando, then you want the "GayDayS" event, which is now being held on August 16-18, 2019. Orlando in August is like visiting the planet Mercury during offseason. In other words, Yes it will be HOT as Hades. If you are not used to the intense sun, you are going to burn. Or melt from the heat like a Cadbury Dairy Milk bar on a hot hob. The host hotel for Gay DayS is now even further away from the Disney parks. In fact, you will be 14 Miles <one way> from the Magic Kingdom (via private taxi). That can get expensive, something else to keep in mind if you stay within the Disney World resort bubble, or at a more affordable Disney Springs resort area, you have access to free Daily Resort/ Theme Park shuttle buses. The daily highlight is the two daily pool parties. You see the men attending GayDayS, their primary entertainment is the DJ Pool parties