200m and 400m sprinting advice.?

[MackJames]

I'm starting to really get back into track and field shape since I've been losing some weight. I use to have a ton of cardio when it came to sprinting, I almost never got winded, but after I tore my hamstring I gained around 41lbs in about a year and half and starting to get into bad shape physically. I'm a little under 5'9 and I weight 210 and my body fat is 25%. I know it sounds REALLY bad, but it's not. I'm actually pretty toned up around my lower body but not so much in my upper body. I can run my 200m at around 22.7 - 23.8 on any given day. My 400m time is around 50.4 - 51.7, I've actually ran under 50 seconds twice. But after each race I feel like I could throw up at the finish line. It usually take me 15 min to recover after a 200 and about 30 minutes to recover from a 400. I just don't know what I can do to gain the cardio back and not be so winded after each run. I eat fruits and veggies and lean meat like I'm suppose to and I only drink water. I stopped eating fast food in January of this year and I have not had nay since. It makes no sense that I eat good healthy food and water everyday and I workout on a regular basis but I get so winded after my runs. Is there any help or advise or training routines anyone has to offer me?? I want to be able to train and run several 200s and 400s without feeling like I need to throw up and stop for an hour. Really appreciate it!