I am in the exact same situation as you.
I was 19 and still in uni, and started dating a 22 year old who has already finished uni and has a job.
Her parents and sisters had trouble coming to grips with it at first, but they got used to the idea eventaully after 2-3 weeks, and we were only together for about 2-3 months.
Its now 2.5 years later, and no issues whatsoever, excpet i have 2 years of uni left,and just want to finish my damn degree get a job and some money so i can marry her already.
And you are deeply in love, so don't let any nay-sayers stop you. Just keep it going, get on with your life and then start a new life with her
My mate and his wifre, They were the same age, but she already had a job and was working, and he was still in uni. She basically supported him whilst he was still studying. He kept going on with his life and then graduated and now they're expecting thier first baby in a few months.
The only downside i can think of is the baby thing, she'll be old and you will have just gotten out of school and it'll be time to have a baby already. Dating somebody younger has its perks, they're young when you meet them, and they'll still be young in many years time. Unlike dating older women, who are already old when you meet them and will get even older in the future.