Brandy, you need new tools that don't include yelling. Listening, validating, expressing your needs, finding mutually agreeable solutions. Identifying the underlying needs and preemtively anticipating patterns that escalate and finding new methods for creating positive mutally satisfying outcomes. I highy recommend several books:
Kids, Parents and Power Struggles
How to Talk so Kids will Listen, How to Listen so Kids will Talk
Raising Your Spirted Child
The Explosive Child
There have been several recent links about children hitting. Two year olds are not socially adept and self-controlled and placing them environments where they are expected to behave in this manner for extended periods of time without constant supervision and redirection is unrealistic, imo. The "socialization" with children of the same age, that is expected of children 2-3 years old ("for their benefit") generally causes more frustration (for child and parent) than pleasure beyond an hour or so from my experience. There are many ways to optimize this experience for all involved. I will try to provide a few relevant and recent links.
But mostly, your reaction is your responsibility and finding calmer ways to interact with your children when frustrated must be modelled in order for them to learn to be responsible for finding calmer ways for them to interact iwth others when frustrated. It starts with you. Only you can break this cycle of uncontolled reactions. As you model and nurture and encourage gentle interactions with others, they will learn this. But "encourage" alone won't do it. You need to model and nurture it as a way of living and interacting with others. I did not have models of gentleness in my childhood family and I had to learn it from other's modeling gentleness toward children. I didn't have the tools. I learned them.
When our son began the types of natural exploration of his reactions, I overreacted and was compelled to STOP his reactions. I didn't understand that his reactions, like mine were due to some underlying unmet need. I needed him to be gentle. He needed more self-control. In time his self-control has become more consistent, but is dependent upon many variables. Just like my self-awareness and self-control are dependent upon many variables. I learned that my biggest obstacles to self-control (and patience)are sleep deprivation and ignoring my hunger signals. And not surprisingly our son's biggest obstacles of self-control are sleep and food needs.
So, I began working to proactively meet my needs for sleep and food and began proactively meeting his needs for sleep and food as a priority above socializing. When his needs of sleep and hunger were not optimal, I knew the social outings would not be as self-controlled as I knew he could be. There was an obvious pattern, but I needed to be in a more optimal place of self-awareness to see the patterns. Protein became our focus. As I was consuming adequate amounts of protein (first thing in the morning and throughout the day) and he was consuming adequate amounts of protein (especially immediately before an outing) both of our 'behaviors' were more self-aware and self-controlled. We discussed how we felt when we didn't eat enough or rest enough and we choose to disengage from added demands that would put either of us over the edge.
Rest was another obstacle for me. I found ways to get a nap because we were nursing every 60-90 minutes all night until he was 18 months old. The No Cry Sleep Solution saved my sanity. Finally, we slept more solidly. Well he was not even actually waking, but I wasn't returning to sleep agter our nursing episodes. So, I observed in my sleep rejuvenated state that ds was not at his best at a social outing when he was nearing a need for a nap. So, it was easy to not place ourselves in overly taxing situations when nap time was impending. It would seem that time at the park wouldn't be taxing for a 2 year old. But with limited toys (I learned to bring more) and limited snacks (I learned to bring more) and many children vying for the same things (and needing naps), and needing to wait and take turns, the duration of frustration that could be endured was more or less dependent upon sleep and food reserves.
You also might find that his nap time has changed to a later time and he isn't ready for a nap at the same time. This may be causing a struggle regarding when the nap is occuring. Nursing was a blessing to help with naptime. After age two, without it, he needed more quiet one on one time to wind down. I imagine that is very difficult with a little baby. I would consider a Baby Einstein video, which is calm and soothing. That is about when we first introduced them, for the same reason.
Do you have any of the baby holders? Carrier, swing, saucer, boopy, bouncy seat, bouncy chair for the baby? You need another set of arms to help ds to bed. He needs your arms. Consider placing baby in the holder for the duration to tend to your *older baby's* need for you at nap time. I am no fan of holders, but they are much preferable to hitting your child for non compliance and inability to have self-control when he is utterly exhausted and overwhelmed. He needs your support.
And my latest lesson that I am continuing to work on is 'holding the space' for me to find that inner calm before I react.
A.........Pause......Breathe.......Think.......bef ore reacting. Finding that space of loving patience that helps you model, nurture and encourage calm in yourself. You can do it. You can learn. He will learn what you model.
And some Rescue Remedy helps when you are too exhausted to think.