Training for my first 1/2 Marathon

Not the most experienced, but what works for me is the following.

The night before my long runs, I have a bagel with peanut butter, an extra glass of water.
Morning of my long runs, I start with a coffee with a tablespoon of butter. 30 minutes later a bagel with peanut butter.

I don't change my preparation other than that. I have been on a pretty steady balance and only tweak it prior to long runs.

Good luck.

I am mainly just counting calories now ( just got back into it). I was planning on moving to more of a paleo plan after this coming weekend. Is that the best option?

Carbs are pretty important for endurance running, so maybe not.

There is a reason the Paleo and Primal websites speak out against the "Chronic Cardio" or "Killer Cardio" with their eating plans.

They can't fuel it with enough carbs, unless you plan on running really slow, even then.....

So find on your Paleo site the links for an article admitting that many people want to do endurance cardio, and a change to the eating plan to allow that.

I agree forgot moving your body to that plan when doing your first half, and not having much base mileage for your poor body.

You don't need to run more than 3, maybe 4 times weekly, you'll just be pushing overuse injury and throw away the race.

If 4 times, one should be a morning while fasted slow run for 30 min. Train your body to use fat stores easily.

Another weekly run should be about 1 hr upper aerobic HR zone run.
Another weekly run should be some intervals for 60 min, but that includes 10 min walking for warm-up and cool-down, so 40 min of intervals. Like 1 min fast then 2 min slow for 15 min. Then slow jog for 15 min. Then 1 min fast then 1 min slow.

Then your big weekend run where you will actually increase the mileage each week.
Usually recommended 10% increase of your weekly mileage. The 2.5 hrs so far may be around 13 miles, with this run starting at 1 hr or maybe 6 miles. So starting out at 20 miles means increase the long run about 2 miles weekly.
6 - 8 - 10 - 12 - that's 4 weekends. Last week should be taper, but have that 12 the weekend before.

Find 1 weekend in there for a foot-time run. Same morning run as the race. Eat the planned way the day before, wear the clothes you'll likely wear, breakfast the same, ect.
Estimate how long you think the run will take you at realistic pace. Divide by 3 for that time.
Now walk 1/3 the time, then run 1/3 the time, walk 1/3 the time. Whatever miles you get is fine, you want the same time on your feet. But not nearly as stressful on your body and fast recovery so you can do your other training days, probably rest day after though.
This will point out any issues - bad socks, bathroom breaks, hydration, bad food choice day before, shirt rubs wrong, ect.

And then 1 weekend is a distance run - same distance within 24 hrs. Make it 15 miles though to increase confidence.
So morning run 5 miles at race pace. Evening run same 5 miles. Next morning run 5 miles. All at race pace. There, just did 15 miles in 24 hrs. Take rest day again after this.

6 weeks is very possible if you had any kind of start to your base mileage, which you had minimal, but something.
I'll be doing the same for a marathon in 6 weeks. Finished a century ride last weekend, so training had been for biking, not running.