Is my 7 in a half month old baby going to starve?

I originally started out EBF him and continued through 6 months. Now I have decided to formula feed. He is doing great on the formula but about 2 months ago I introduced solids and he has been somewhat hesitant on taking them. I can barely get him to take different baby foods and I am really concerned. I just dont know what to do. Can he get proper nutrition from formula. As I said he will eat solids sometimes but for the most part my son will not. When he was born he was 9 lbs 6 ounces and right now he is about 18lbs. In the beginning he was gaining weight fast but it seems now that he weight gain has slowed down. He also looks somewhat thinner but attribute this to him being more mobile and attempting to crawl. I am just worried. I have also tried rice cereal and baby oatmeal but he just does not want solids. What should I do? I dont want to be a bad mom who only gives her baby formula.