I believe Pepcid is an H2 blocker, which works differently than a PPI (like OTC Prilosec, as dbab has suggested). Once PPIs were developed GI doctors moved their sufferin patients to them, and left H2 blockers behind to act as back-up for people who need something in addition to PPIs, or those who are sensitive to them.
If Pepcid is working, that's great. If you find that it stops being as effective you could try an OTC PPI like Prilosec. They also make some PPIs generically, so they're less expensive than name brands.
Even more important than the meds, though, are lifestyle changes. There is lots of information on the internet regarding how to treat GERD with changing what you're doing. Here's one of them:
You said that you "tend to eat pretty bad stuff". That is your first job...work on changing your diet. Taking acid reducing meds while continuing to maintain an unhealthy lifestyle is not an answer.
Wish it was easier!
Hang in there, and I hope you get some insurance very soon.