I love my solo trips! Like you, I was a bit hesitant when I first decided to do it, but it was so much fun when I got there!
For your days, I'd do February. I like Feb for a few reasons. First, it's when I typically go. In fact, I'll be 2/20 to 2/24 this go round. The hours are a little "nicer," meaning they open a little later (sometimes 9am or 10am) and close a little earlier (8pm to 10pm). That helps me be there open to close, feeling like I haven't missed anything, but still get a full night's sleep, which lets me return from my trip at least as rested as I was before I left
Most of the rides are up and running, except, most commonly, Grizzly and Splash. Of course, some things will be down for refurb, but not as many as January! A lot of the rides have been, or will soon be, up for refurb, as everything is getting cleaned up for the upcoming opening of SWGE (Star Wars Galaxy's Edge).
As far as advice/experience/insight/calming techniques... Sorry for the upcoming novel. I'll try to keep it short.
Like I said earlier, I love my solo trips, and want others to experience the same wonderfulness!
Hotel: I'd go for the cheapest. Both are safe and close, and nice places to stay.
Use single rider lines (SRLs). Let me try to remember where they have them. Matterhorn, Indy, Space, Splash, Grizzly, Incredicoaster, and... I'm forgetting some off the top of my head. At any rate, use them! Some are quicker than others, but they most often seem much faster than a regular line.
Find something that you want to do for just you. For me, that's a nice restaurant or a park tour. So, I stay at a "cheaper-ish" hotel, and use the savings for a special me-treat. I'm a wife, I'm a mom, I'm a grandma, I'm an employee, I'm a small business owner. But, for my few days at
Disneyland, I don't worry about what my husband or daughter wants to eat. I don't worry about where my grandkids want to go. I don't need to make considerations about my work or my business.... I get to do a few days where I can do what I want, which helps me recharge so that I can return with much more energy to give all my other titles my "all."
Use MaxPass! Make use of the PhotoPass feature, too! The photographers have always taken some extra pictures for me, so, even if I don't like most of them, there's usually 2-3 that I find that I really like.
Consider doing things you wouldn't spend time doing if you were there with others. Ask to ride in the nose of the monorail, or the wheelhouse on the Mark Twain. Eat an ice cream on a curb while waiting for a parade. Finding spots to sit/stand for parades are REALLY easy as a solo-ist; most people will scootch over for just 1 person, where they wouldn't if you were trying to find a place for 2-3 people.
I keep a Hidden Mickey book in my purse for the fun of it when I'm just wanting some quiet exploration time. This time, I found a scavenger hunt book for the parks that I will be taking with me to learn some new things that way.
Have a great time!