Best baby turned into worst baby😔

Bay • 18. First baby. Taken by the love of my life.
When I was in the hospital and a few weeks after we came home I had the best baby I was able to take him to movies, out to eat, literally everywhere, and have people come over to see him, but after a he was a few weeks old it was like a switch changed and everything has been going down hill. I love him to death don't get me wrong, but I'm so tired of a grumpy baby. I can try EVERYTHING to try to calm him down and he'll scream his head off its not just a little mad cry it's a pain cry and it makes me feel horrible and sick to my stomach that I can't do anything. I don't even know how many times we've been to the doctor because his cry sounds so horrible I even took him to the hospital once because my mom came over and she said something was seriously wrong even thought he might have a hernia just to be told he has collic. It's not like collic though it's a ALL day thing. He's 3 months now so that's over 2 months of a cranky baby. I can't go anywhere or do anything anymore. Everything he use to like is a hit or miss depending on the day. He use to love car rides now he screams the whole way, use to love being rocked to sleep now he hardly ever falls asleep while I rock him. When he was a month old we had to put him on a acid reflux medication then he got a ear infection that wouldn't go away because he's always got a stuffy nose so he has to stay at a angle constantly. I'm 18 and trying to go back to school to get my aerospace and aeronautics engineering degree done with I already have 3 years done, but I'm afraid to leave him with anyone because he's such a difficult baby. I'd hate myself forever if something happened to him. It's always on my mind that someone isn't doing to be able to handle him like I do. His dad's deployed right now so I don't have much help. He'll be able to skype here and there and he's always happy for that... Does anyone have any tips or have a baby who suddenly just switched? He's seriously the only thing that makes me so happy even when he is grumpy, but sometimes I feel like he's not going to grow out of this 😔