First off, please ignore any typos in this post. It's been a long day and I'm not focusing
Alright. So for a first horse I ALWAYS reccomend a gelding who is on the older side. 15 or older is generally really good for a confidence builder. Obviously stallions are abad idea and mares never lose the stubborn "I wanna do things my way" attitude that most human females have as well.
Although there is no breed that is more relaxed than the toher, as a general rule I like Quarter Horses for beginners, although it really doesn't matter. QH's can be hot just like any toher breed. They are just mroe well know and stereotyped to be cold blooded.
You will want a horse who is very calm, very gentle, and very forgiving. One that doesn't spook at all. See if you can fidn yourself a good sound kid-broke horse. That's what I did for my cousins who were scared. Granted they actually are kdis, but adults can easily hop on a kids horse too if they are sound enough, and any kids horse is worth their weight in gold.
As for easing the fear, just spend some time walking in circles. Maybe ahve someone elad you around or put you on a lunge line so you can walk circles with someone else holding the rope. Once you master the walk, try trotting. Then get off the lunge and try riding on your own. You'll get better and more confident when you realize "Hey, this is easier than I thought!" and then you can advance your way up the ladder.
And OF COURSE you can push through these fears! Fear is a natural reaction your body creates to protect yourself. You jsut have to tell your body that there isn't anything to be afraid of!