You're almost there. You missed namespace.
Type myType = Type.GetType("System.String");
object[] atts = myType.GetCustomAttributes(true);
In your case
Type myType = Type.GetType("YourNameSpace.MyClass");//this should work
Refer Type.GetType for more info
var asnames = Assembly.GetExecutingAssembly().GetReferencedAssemblies();
var asmname = asnames.FirstOrDefault(x => x.Name == assemName);
Assembly.Load(asmname);
Use the above code to preload the assembly(If it exists in your referenced assembly)