should I leave my wife?

my wife and i got married when we were 22 and got together when we where 20. now we have been together for 4 years. She is a great person, loving, faithful and caring person that only wants to see me happy. But I feel like she puts all of her hopes, dreams, happiness in me and i feel like its a lot to handle. My wife has been wanting kids for that past 2 years and i have been trying to tell her in every way possible, even coming out and saying i dont want kids until im at least 30 to 35. i dont want to waste my 20s being a parent. not that there is anything wrong with people who have kids early. This is just my opinion and the way I feel about it. Her family has welcomed me with open arms and are a much more oriented family than my family is. I'm not jealous or anything like that. I miss being single and the freedoms it has. I'm not much of a partyer so its not for that. Even when we got together, at first i was just looking to get some... i know that sounds wrong but its the truth... then i proposed to her cuz we were in a relationship for 3 months and that just felt like the only thing i havent done. durring the time of engagement i wanted to wait 2 to 3 years before we got married so we didnt set a date. but she kept hounding me about it until i finally caved and then when it was upon us i wanted to push it back but she didnt and i went through with it anyway. I am a selfish person and i know that and every year or so i have these thoughts of leaving and we get into a fight when i tell her and somehow she always convinces me to stay. I dont find her attractive and she does not like oral sex when i love it.giving and receiving, and 80% to 90 % of the time her vagina isnt so fresh if you know what i mean. we only have sex like 1 time a week and sometimes not even that. I want her to be happy but i feel like she is always found wanting in my eyes and she knows it. and that is not fair to her. I feel like i am wasting her time when she could be out there finding someone that wants the things she does and that can make her happy and give her the things she wants out of life, but she always says she is happy with me and has said that she will wait to have kids, but i know she just said that to make me stay and i dont want to deprive her of being a mother when she wants to be one so badly. i know that because now she is wanting to do this fertility diet. we have a house that her father inherited and i pay for the rent and i have also put thousands of dollars into repairing and remodeling it. also i had to buy new appliances for the house as well. i say i because i make 80% of the income not that thats a bad thing the man should be the provider. sometimes i feel like im stuck, i feel like if im not attracted to her now being overweight how am i going to look at her in 10 years when her matabalism slows down and she has a couple kids and gets bigger..... i have tried getting her to lose weight, we go to the gym, try and eat healthy by tring i mean we eat healthy and splurge every now and then but she sneaks things and doesnt tell me about them or she will eat them in front of me even after i say something like we really should not eat candy before bed or have a starch with dinner. we also do MMA together but she still has not lost any knoticeable weight and we have been doing this for 6 months. I care for her and i want her to have a happy life.....sometimes i feel like a douche for feeling this way but i feel like we dont want the same things, we hardly ever fight and she is a great friend and i would love to remain friends even if we were to divorce. I feel like kids are only going to complicate things on a whole other level. and i am not ready for that. please give some advice, marrage counseling we looked into and im sorry i dont have the money for 70 dollars and hour thats more than a days pay for me, which is the cheapest in my area.....it so that is not an option. i feel like i should leave so she has the chance while she is young to find someone else....im so confused what should i do????