Do you have the Montgomery GI Bill or the Post 9/11? If you still have the Montgomery and haven't converted, you have the option of going to a Part 141 VA approved flight school to get your ratings. In that scenario, 60% of your training costs are covered. You are on the hook for the other 40%.
If you have already converted to Post 9/11, there is really only one way to get your ratings that makes sense and that is to get them at a college while getting your associates or bachelors. In that scenario everything is 100% covered plus you get a book stipend and a housing allowance based on the number of credits you are taking. The other way is to use a Yellow Ribbon program and you are limited in what you can spend on that. I don't know much about that so you would have to ask someone else.
When I left the military I had a choice since I still had the Montgomery GI Bill. Despite already having a Masters degree and not needing another degree, I chose to convert to the Post 9/11 GI bill and get my training in pursuit of an Associate’s degree. I did this for a couple reasons. First, I would occur no debt since everything is paid for. Secondly, I would then get a reduced ATP of 1250 hours. The negative is that it would take me about 6 – 8 months longer to get all my ratings. Due to my Undergrad degree, I was able to get all my Gen Eds credited so all I had to do was the flying (I already had my PPL like you when I entered) and take the aviation specific classes needed for the degree. I will complete everything this summer, 18 total months.
It all depends on your stiuation and what works best for you. If you have a large family that you need to support, then going back to school may not be an option for you.