Service dog

My name is Kelsey and I was born with Chiari Malformation.  This is a malformation of the skull.  Chiari has caused deblitating headaches, dizziness, blacking out, numbness in my extremeties and many other symptoms. Two years ago I had 2 brain surgeries within 3 weeks to help with the symptoms.  There is not a cure for Chiari Malformation.  Along with Chiari Malformation I have several co-morbid conditions.  These are Cranial instability in the cervical junction, a neurogenic bladder, Ehlers-Danlos Syndrom (this is an autonomic nervous system disorder that causes joint pain and many other issues), and dysautonomia.  Dysautonomia causes me to have a very high heart rate when resting and causes my blood pressure to be low.  Just like the Chiari Malformation, none of the co-morbid conditions have a cure.  These are issues I will battle my entire life.  Chiari Malformation alone is life altering but when adding the co-morbid conditions as well my life is very different from other 18 year olds.  
I depend heavily on my mom to go with me places because I am afraid of having a flair up of the dysautonomia (high heart rate) or getting a bad headache, and blacking out.  I am unable to spend more than 30 minutes in the hot Texas heat, I am unable to exercise and am on a special diet to help minimize symptoms.  I can't not carry anything that weighs more than a jug of milk becasue it causes my head to hurt.  
I am about to start college in August and would like to be able to attend college on my own without my mom having to assist me.  Therefore, I am campaining to raise money for a service dog.  Service dogs are very expensive ($20,000 plus travel expenses).  By having a service dog they can alert me to heart rate changes so I can take measures before it gets out of hand. A service dog will also be able to help me when dropping things as bending over causes great pain for me.  A service dog will allow me to have the independence that I long for.  It would help me with anxiety attacks that care caused by all of my medical conditions. 
Thank you in advance for your help in me obtaining a service dog.