I had a very similar situation I had got my braces to close my gap. I wore my braces for about 2 years. When I was given my retainers my ortho told me I had to wear it in my mouth for 24 hrs a day for one full year and after a one year I could wear it at night. I didn't listen to my ortho, during the first year I would only wear it at night because wearing it during the day was too much work plus i spoke funny and I would salivate when I had them on.I would notice that when I wouldn't wear it during the day a little gap would appear and when I would wear it at night it would close my gap by the time I woke up in the morning. The retainers are meant to keep your new aligned teeth in place don't forget your brain has to get adjusted to the new alignment of your teeth so if you don't wear your retainers your teeth will try to shift back to its original placement. I don't think you need to wear braces again but it does depend on how long you have been prolonging the problem. I think you should visit your ortho and bring up your concerns but more than likely your ortho will tighten your retainers and tell you to wear them accordingly. As for me I solved my problem by getting veneers but I wouldn't advise you to do that until you are financially capable. Good luck!
A retainer is meant to keep your teeth in place NOT move them so it's unlikely that it'll help too much. But if you're teeth haven't moved that much there's a chance it could help so put them back in- there's no harm it trying.