I need help. My kids need socialization, but I hate taking them out because they are under-socialized.

I'm in tears now and will try and be as honest as possible. I am using a throwaway.I have two kids, 5 and (almost) 3. My 5 year old, boy, is in 1.2 day Kindy, my daughter is at home with me.My five year old is such a handful I don't know what to do. He has such big emotions and challenges with any kind of transition. My nearly-3 has a temper on her that matches no other.I have zero family and few friends that are stay at home parents, and those that are are so invested in activities (soccer, music, hockey, Spanish lessions, ect) that it's hard to connect. WE do drop-in stuff because I'm so fucking lonely, but my kids are so demanding I usually spend all my time with them or have to leave.Example:This morning I met up with a mom and her four kids in a playground with some other parents/kids. My daughter got angry over her snack and absolutely lost it (she was tired) and screamed for ages. I tried to hold her, cuddle her, walk around, give her a different snack, ect but she kept screaming and all the other moms were watching me. I felt like such a failure. I have no clue what I'm doing. So I decided we needed to go home and told my 5 year old and he got so angry at having to go home that he started shouting at me and saying he wouldn't go home and ran out into a field. So I have my near three year old hitting me/ pulling my hair/ scratching me/ SCREAMING and I'm trying to get my other kid to come back so we can just leave and he won't, and I just felt like the shittiest worst fucking failure.I don't know what I'm doing wrong. I don't know why it's so hard for me and seems so easy for others. I quit my job to stay home and feel like I have spent five years trying to be a good parent and I'm exhausted from apologizing for their behavior and feeling like a bad parent because unlike their peers, they don't listen or respond to me.I have met with doctors and my 5 year olds teacher and she has said that my son is extremely bright he struggles with group activities and transitioning betwene one activity and then next, and goes from zero-100 in a heartbeat. We have had him tested and he isn't on the ASD spectrum.I don't know what to do. I'm just so lonely and so exhausted. I try and take them out all the time and it just never seems to go smoothly. But the few friends I have to see during the day don't have any of these struggles so I have no one to turn to.I want to just not leave the house with them again, but I know the only way they will learn how to socialize is by being with people, so I feel trapped. I once has a very people-oriented job I was good at, and consider myself an extrovert, so this is so hard.Thanks for reading. via /r/Parenting http://ift.tt/2oOVTZn