If you've been in the Phils for months and can't get laid, you have some fundamental problems. It's hard to tell from your post what these problems are. However, it's very clear that you have them. To put it bluntly, a man in his 30s who can't get laid in the Phils (probably the easiest place in the world to get laid) has to be a complete and total fuckup. Whether it's your permanent state or something that can be easily fixed I have no idea.
Your question about girls in their late 30s. Yes, you should avoid them. In your mid 30s in the Phils, you should focus on girls in their early-mid 20s, maybe late 20s but not older than that. There is simply no reason to waste your time on older women unless one of them throws herself at you and passes the boner test. Generally speaking, compared to younger women, they look worse and have more mental issues. More importantly, they are not easier than younger women, can be more difficult other things being equal.
Your question about girls in their late 30s. Yes, you should avoid them. In your mid 30s in the Phils, you should focus on girls in their early-mid 20s, maybe late 20s but not older than that. There is simply no reason to waste your time on older women unless one of them throws herself at you and passes the boner test. Generally speaking, compared to younger women, they look worse and have more mental issues. More importantly, they are not easier than younger women, can be more difficult other things being equal.