I have a qualifying race in 3 months and a championship race in 4 months and I'm a little overwheight with 15-20 pounds of fat to lose and I was wondering if it's still possible or is it already too late?

Ideally in healthy way without getting injured or having to lower my mileage not to get injuried.

Don't worry about losing muscle. You will lose some, it's not a big deal. Your body works that way - it's either generally catabolic or generally anabolic. What you can do is:

- be in a slight calorie deficit. more is not better here. -500 a day is your maximum
- eat more protein - this will spare some muscle
- doing low intensity (long slow jogs are ideal) activities on an empty stomach will help
- add coffee and yohimbine for better effect for those jogs
- don't worry too much about specific numbers - you will get close enough to your optimal weight in 3 months if you do everything right, but it might be not what you had in your mind

I lost a lot of weight when I bought testosterone propionate online. It's probably not the healthiest way to lose weight, but after I did it, I started running and exercising every day, and I have to confirm that I lost over 20 pounds. I'll leave you a link to where I bought it, https://steroid-pharm.com/testosterone-propionate.html in case you're interested. Now I live a happy life about my body and follow a diet. it really changed my life for the better.