Ok Im going to try and make this as short as possible...
I have been dating this person for 4 years and I love them very much. However I feel like since being with them I haven't gotten very far ahead actually I feel like they have brought me down several times. I look over that because I do love them and I don't mind helping but what about when I don't feel I'm being helped. We have been through so much and I feel like most of the time I have bailed us out. For example through the entire relationship we have always depended on my vechiles because there's always tears up or they tear them up or wreck them. Well now I have two vechiles and they are using one and it upsets me cause I know they will abuse it and it will be gone too! I ask them not to drive it all the way to there job because they can carpool but they sometimes do anyway! This angers me... I am considering throwing in the towel because I feel like I mother them and perhaps there is a point where enough is enough but I really love them... what would you do

This does not sound like a healthy and equal relationship,
Why will the not share and car pool ? Why have you not taken use of the car away, if they will not be considerate.

From what I am reading, you are not happy or satisfied at all. I also don't really think you love this person. I think you believe you love them but I also think you are confusing that love with what hopes you had for them and your relationship in the beginning.

You are probably better off just cutting your losses at this point and move ahead with your own life. There is someone out there that won't take advantage of you and will treat you the right way. Find that person and don't just settle for someone.

Good luck.

You are not in a healthy relationship. You are enabling them by allowing them to use you. Your not their mother figure and they most likely 'love you' for your enabling them to not have to get ahead in life. I lost everything I had on a guy in a relationship just like yours and it doesn't go anywhere but downhill