Hey Shawn! Good to see you in here, instead of just following your youtube!
Summary: my best recommendations for picks… find a store that has a ton of them and sells individuals, literally buy one of each and find what works for you. Prob will cost around $5-10 USD to get like 30-40 depending on the store/pick.
The needing to readjust seems to be normal, I’ve found it fades with time. A useful tip someone gave me, was to always have a pick on me, and just play with it (flip it around in your fingers, over fingers, rotate it around, etc) when you’re not busy or doing something idle that doesn’t require your hands. Since I started doing this, I’m finding I have better control when playing.
I’ve discovered that I have a handful of picks now that I like for different styles… some picks sound warmer (Dunlop nylons are in this category)… some have a sharper attack and sound brighter… some are great for flat picking, others better for strumming. For scales/electric I’ve been playing with various smaller jazz picks (ie: Dunlop Jazz III I have and really like, the Jazz III ultex is my goto in this category right now, also I’ve become a fan of the Dunlop “Subby”) and also playing with an Adamas Graphite 2mm.
For strumming, I’ve been using the Tortex Flex (did you mean you ordered the tortex flow or flex?) series instead of the regular Tortex more often than not, as I work on transitioning to a thicker pick for strumming again… I’m finding them to be great for transitioning to the next level of thickness… so right now, instead of using a regular tortex .6, I typically use a tortex flex .73… but you can also keep it at a tortex .6, I switch back and forth depending on what I pull out of my pocket first. I’m also a huge fan of the Dunlop Ultex series (I also find these can be a little grippier than the regular Tortex’s), if that comes out of my pocket first, I get excited lol. I keep a few favorites in my pocket at all times, a couple thicker picks for electric/scales/picking/etc, and a few for strumming.
Of the above, they do have different sounds… Nylon is more forgiving on pick style, and tends to be softer on “attack” (so less harsh if you hit hard) - I used these for a bit up until a few weeks back, but they were slipping out of my hands too, even after I had mostly stopped dropping the tortexs weeks earlier 
… Dunlop does make a “max grip” vs of their nylon picks that have a bunch of little grip bumps on them. These are less slippery than the regular, but I still find if I’m playing for awhile, they slip.
Those are some of my currents above. As mentioned, the pick you use will affect the sound that comes out… esp with acoustic/strumming. Sometimes, you can get a warmer sound out of an otherwise bright acoustic guitar by just using a different material pick or a brighter sound out of a warmer-sounding acoustic. The same basically applies to electric, but typically you would want a thicker pick for electric I’ve found, even for strumming.
Do you have any music stores near you? If you’re near or in a city or even a town with a few music stores, ring them up on the phone and see if any of them sell individual picks. Then just go down and check them out and maybe get 1 of each, figure out which ones feel best to you, then play with them and listen to the different sounds/dynamics you can get playing what you already know. I read this advice on some forum about a month ago, and whenever I’m in a new music store, I check to see if they have any picks I haven’t tried now, and I’ll grab 1 or 2 (they only cost about $.10-.30 for most, some of the really nice ones may cost like $1, Justin mentioned in one video that he uses a $40 pick if I recall correctly… I haven’t even seen a $40 pick at any store, so you can probably avoid that one for now 
