child fears and nightmares

I am sitting here watching my beautiful baby boy (2yr old) sleep. He is amazing! Full of energy, very friendly and extremely affectionate :-). However, he has many unusual fears. He was terrifed of feathers and leaves at one stage for a while, so I started using them in some fun activities. He is slowly getting better in regards to that. He is afraid of our neighbours dog barking and thinks he will come into the house to get him, he becomes hesitant to go outside (on our property) to play, the dog can't even be seen! And isn't right next door, there is a paddock in between. At our previous house, he was afraid of how the ceiling looked. It was almost like it had floorboards as the ceilings which had all these dark markings on it, he would scream the house down! Some of the markings looked like faces. I take him to McDonalds and the playarea has all those tunnles and slides etc.... he gets scared to go in becsuse he feels that someone will chase him inside. He also has nightmares :-( Last night was one of the worst! He woke up screaming, my husband and I went in and he was sitting up in his bed facing the wall, screaming "Spider Spider, it's coming!" And he was looking at his hands saying "Look Look, Get it off!" Then he looked all around his room, pointing everywhere saying "There There Spider!!!" I was so scared for him, we spoke calmly to him. He was shaking with fear and couldn't even talk properly. Then I realised that last night before the kids went to bed, they watched Peppa Pig, which had a spider in it. It took my husband and I two hours to settle him, then he was up at 5.30. He is actually a bit unwell at the moment and I find when he is sick he has terrible nightmares. I just dont know what to do. He also watched The Wiggles and was terrifed of someone dressed up in a camel costume. I know it sounds silly but when he's in that fear state it is extremely distressing. I want to help him, what do I do? Is this something to go and see a doctor about?
Thank you all so much for taking the time to read xx