Why can't my kids react normal??

You all know Jeffery has a speech issue, so he gets easily frustrated...which leads to meltdowns. I should say SOME of his meltdowns is due to his speech, not all. Jeff took Jeffery to the store and got him a chocolate milk and told him to hold onto it, well he ended up sitting it on the arm of his booster seat...when Jeff pulled into the driveway, it spilled EVERYWHERE....Jeffery KNEW better, but he did it anyways. So Jeff had to bring him in and give him a bath....when it was time to get out Jeffery threw a FIT, splashing the water, screaming, and hitting....we understood him when he said he didn't want to get out, but he HAD to get out, he had time to play and all that fun stuff, and we let him know we understood him, but daddy said it was time to get out...it was an all out war to get him out! He knows he only takes a bath for a limited amount of time, but everytime he throws one of these tantrums. It seems like overkill. That is just 1 example of a tantrum, there have been days I have had to carry him kicking and screaming, throwing himself all over the place, to his room so he could go where he couldnt hurt anyone else or himself (yes ive had to do this while pregnant, and ive been worried his tantrum would hurt me, the baby or cause me to go into labor preterm, but i had no choice) He HAS hurt me, he has hit me in the face sooooo hard and i cried because it hurt, he's kicked me in my knee and almost bent it backwards, he's also kicked me in the belly and i was terrified he would hurt the baby. We've tried timeout, but can't keep him sitting there, ive held him, but ended up getting hit or kicked, ive spanked (last resort) and it dont phase him, ive taken toys, tv, video games, everything away from him, nothing works!!! Ive seriously broke down in tears because I was at my wits end, ive had to put both kids in their rooms because Jeffery was throwing a tantrum and made Jaylin cry, so in the end all 3 of us ended up in our rooms crying. We had him evaluated for ADHD and of course they say he's too young for that yada yada. He has issues with sensitivity to touch, his security blanket has to be a certain side down for him to sleep, he can feel the difference. When we were at the beach, he said the waves were too loud and he ended up holding his ears. He lines things up constantly.....a lot of those are red flags for Autism...I'm trying to find a decent place to get him evaluated for it. But it seems he only acts up for me and Jeff...he's fine in school, fine for everyone else. I feel so lost, my 4yr old is out of control and there is nothing I can do!

Now, Jaylin she's a different story. She cries over EVERYTHING! She is seriously attached to mommy. She is 2 1/2 and still dont understand "if you do this, you get that" if she cant get something, she dont understand she has to do something good to et it (example, pee in the potty for a sticker, finish food before dessert, ect) Jeffery knew all this stuff by this age, heck he was potty trained at this age! Yes i know, all kids are different. I know some of her issues are due to her having always been sick from May 2008-March 2009, between those dates she had 2 sureries (tubes in her ears, and tonsils and atnoids taken out). Her speech is seriously behind, which we're currently getting her evaluated for, and I decided to go ahead with a full evaluation to find out if there is anything else she's behind in...I know social is an issue, she dont like other kids at all. She dont share, even though she has a brother we force her to share with, and have been doing that since day 1! You can just look at this girl wrong and she'll scream and cry like someone is killing her. Just this past week she started hitting her head on the floor when she throws herself on the ground.

I worry, a LOT. To me there is something not quite right with my kids. I love them dearly, but their reactions to things are just odd to me, and I've been around a lot of kids, all different ages, and I dont recall any of them these ages acting anything like my 2 do. I'm not saying both, or even one of my kids may have Autism, I'm saying they both show SOME signs of it....I'm saying I think there is just something odd about my kids. I just want some answers, some help, anything to help get through this.