Horse fear?

i have a horse that i've had since last august. the first time i got on her she tried to scare me and it worked. but i got back on her and she has done fine but my husband and i went riding 1 day and she was limping so we came back to the house and checked all her hoofs and they were fine so i climbed back on her and she was still walkin a lil funny but my husband says his brothers horse does that when he doesnt want to be rode so i stayed on her. she finally got out of the limp and was doing great but on the way back to the house she went completely nuts! she started twisting back and forth and throwing her head around and almost started bucking but i got her calmed down before she could. well we finally made it back to the house and she did fine on the way! my question is what was her problem and now im scared of getting hurt so how do i get over that fear? i want to ride her but im scared of getting hurt and im also unexpierenced. plz help. any ideas will be great!!