8 months old solid feeding

hello mummy, my son is seven months plus and he only eats cerealac. I have tried giving him some other home cooked puree and it seems he doesn’t like it at all. Fruits and vegetables like sweet potatoes or watermelon he still doesn’t like it. Each time I make him try new food he will give a face like he’s about to puke. I don’t mind giving him cerealac Every day but what if he starts to grow up will he be rejecting any other foods? I’m so stressed right now what should I do?