Cheer up, it is never too late to learn and it does take time:) I am in my 50's and I am learning languages:) I also hav felt like that but you and I are not stupid it just takes time to learn and some people naturally learn quicker than others. Some people have more time than others to learn.
All the best with learning anyone who feels like this. If I can learn and others at my age, then you also have much to hope for!