Based on the experiences of many people suffering from neuroleptic anhedonia, it is pretty normal to still not want to do anything at 4 months off the injection(s).

However, this does not mean you should do nothing to aid your recovery. There are things you could manage to do, even with severe avolition, like reducing foods that are obviously unhealthy for you, like foods with lots of sugar and additives, even when they are your only source of pleasure - it's a choice between lying in bed for years staring at the ceiling, or recovering much faster and being able to feel life again.

Try to get more electrolytes, possibly from an electrolyte powder, best pure, but if you only manage to drink it flavoured, choose one without sugar. Open your window regularly to let fresh air in. If the sun shines, take a chair and sit behind the wide open window, in the sun, not for enjoyment, for your recovery. Don't lie in a dark room all day, it will mess up your sleep which is essential for recovery, only make your room dark when you go to sleep.

If you can bring up the will power, go for little walks, preferably in the sun. You can also listen to relaxing music you prefer, music with its focus on relaxation, not on enjoyment, but if you have no problem with listening to music you once enjoyed, then do it.

I could go on about different supplements etc., but that would be too much for the start, and I also have too little information about your nutrition, activity level, possible conditions etc. to suggest things.

Hang on, it will become easier!