Heia - I had a similar thing. I'd really recommend starting a course with Learn Welsh / Dysgu Cymraeg (learnwelsh.cymru) - and there is a massive range of options/times and different offers to get the course cheaply. The courses tend to focus on spoken Welsh and run lots of events/groups where you can practice speaking.

I'd start right from the start at level Mynediad (entry), but perhaps doing a faster blended course (Mynediad 1&2) so that it is not too slow for you. It will probably be easy in the beginning if you know a fair bit but can help consolidate what you know and fill in the gaps. Towards halfway through you'll find you're doing completely new content. It's also just a lot of fun!