Firstly, old tech works just as well (or in some cases better) than modern tech. Just because something gets superseded doesn't necessarily mean that the newer product is actually better for getting a job done.
Also, I was diagnosed with being dyslexic back when that was in fashion. Knowing people who are dyslexic, I think i'm something else, but I certainly have had serious problems with handwriting.
And in perfect seriousness do try writing with an old fashioned dip pen. I started because I got into reenactment and wanted a bit of practice outside of using them at events. I ended up coming to the conclusion that Biros are evil things that encourage if not require poor handwriting. They allow people to hold the pen improperly. Holding the pen improperly largely causes bad handwriting. Did anybody tell you that at school? No? Me neither.
With a dip pen, if your holding the pen at the wrong angle it simply doesn't work. That forces you to hold the pen at the right angle, and that means an instant and significant improvement in the quality of your handwriting. As you get used to it, it gets steadily better, especially if you do a few sheets worth of copperplate calligraphy instruction pages then you'll discover that your handwriting suddenly goes from being abysmal to being somewhat better than most peoples.
Hence my desk at work now has several inkwells (you can get beautiful antiques for a pittance because your one of the the only people in the country interested in them) and a collection of dip pens with different nibs. (each gives a different effect when writing) If you have trouble remembering to take your hand off of the paper and move it, just put less ink on the pen. It'll run out and force you to move your hand to dip the pen in the ink again. You'll get used to moving your hand after a while, and fully dipped a fine tip can easily last a page of A4. IMO dip pens have a undeservedly bad reputation.
Lastly, if you do decide to go down this route, get yourself a mini hot glue gun and a wax seal from ebay. Wax sticks fit a hot glue gun, so if you are required to fill in forms then you can fill them in with a quill, fold the form and wax seal it shut and then snailmail it just to make a point to people that they are being overly archaic in not allowing you to email it, and that you can play too.
If you can act, you can also then quietly mock green types (who still use biros) when they ask why your using a quill by pointing out that the feather (or wood) holder is bio degradable, the nib is replaceable, the inkwells have an age greater than the combined total age of everybody in sight and unlike them you aren't using a single bit of single use plastic. (and did they realise that a biro has four bits of single use plastic that go in the bin when replaced? The outer case of the pen, the ink in the tube is in a plastic tube, the cover and the bit on the end of the pen; all of which go in the bin every time you get a new biro)
You can get near endless entertainment out of being slightly archaic.