Glad you're thinking about this Orys...you record a lot of good stuff
Releasing music is one thing, promoting and/or selling it effectively is another. Your initial costs for doing both can range from very little to thousands of dollars, depending on your fan base, the format you choose, and how much work you need other people to do.
In one sense you've already "released" collections of your music on Soundcloud, so now is a good time to consider what your next goals are. For example: Are you trying to find gigs? Gain online fans? Sell your music at shows? Get DJs to spin your tracks? Find a label to release and promote your music for you? Etc.
Considering these questions can help you figure out the best approach. It's fun but can take a lot of time and effort, so think about what will get you closer to your goals.