You need to take chem 2, ochem 1/2, and phsyics 1/2... that a decent amount not to have completed. You essentially have 4 semesters to take them: this summer, fall, spring, following summer. Make sure you can fit that all in before applying. IMO, I wouldn't apply this summer.
I assume you haven't taken micro or biochem, which I think some schools require or "highly recommend" now.
With your current situation, you would need to have a completed application (includes DAT) ready to be submitted right when it comes out. If you take the DAT in July, your app is not complete and won't be reviewed until the DAT scores are received by the schools.
This is all besides the fact that you need chem 2, ochem 1, 2 to do well on the DAT. Can you teach yourself all that material and study it and the rest of the material to be ready for a June or July DAT (which would be late for you anyways, imo)?
Will you have time to take upper division science courses that schools do look at? Some specifically say the more the better.
What if you don't improve your GPA or actually hurt it? How many schools are you going to apply to? Have you shadowed?
You really haven't provided much information. I think it would be a waste of time and money to apply this cycle unless you think you can really pull it off.
Best of luck.