Setting a time limit on progress for stuttering might not work out the way you expect. Im not exactly sure how tangible your goal is, what does it really mean to totally overcome a stutter? But I think its a good idea to utilize your free time. You have a sense of what is easy and what is difficult for you. I suggest you continue pushing yourself on what is difficult. Find opportunities to talk to people you don’t know, you can easily incorporate this into trying a new hobby or activity. Try not to avoid L and G words, even if you stutter on them thats fine. Getting used to the discomfort and being okay with it is really empowering. you could also practice tongue twisters that use those sounds. Some people find those exercises helpful, some do not. The other comments here so far have good suggestions. Mindfulness and expressing yourself without speech (like journaling) is good for more than just stuttering. Enjoy your month off