My 3 month old grunts and wiggles from gas from 2am to 6am, and has been doing so since 2 weeks old. Tried everything. Will this get better soon?

Grunts and wiggles. If your baby is sleeping with you , put him in another room so you won't hear his wiggling. Secondly, you might swaddle him before you put him to bed. Third, have you given him anti-gas medication. In the end he will do just fine. Dont despair.
Normal variation. It is likely this bothers you more than baby. Ignore it. Never place blankets, bumpers, pillows in the bed with a baby after 1mo or as soon as you can wean them from swaddling. Dozens of babies die every year in the US after suffocating in their bedding.