4 month fussiness— needing some encouragement

Y’all. My sweet boy will be 4 months on the 24th and holy cow the last 2 weeks have been ROUGH. We get smiles and joy for periods of the day— so I know that sweet boy is still in there, but man on man is he fussy. We thought it might be constipation— he used to poop once a day and now it’s like once every 3 days (exclusively pumping and eating really well— about 30oz a day) but prune juice, Reguline formula, warm baths, nothing seems to help— I just think he’s fussy for no reason? Could he be teething? He is constantly chewing on his hand or blanket or shirt— but I heard that was normal for this age. He did learn to roll over this week— both ways— so I know he’s doing a lot of developing… I guess I just need encouragement that he may just be fussy because of this stage in his life and he won’t be fussy forever?! I’m a fist time mom and I’m feeling like I’m failing 😞