My 3yr old has been acting out more than usual, I am a single mom and feel terrible punishing him all the time. Should I take him to a professionalk?

Big stuff or little. Divide the behaviors into the "big stuff" and the "little stuff". Big stuff are those things that are not negotiable- hitting, biting, throwing things, dangerous things. Pick up your child and put him in time out (1 minute for age). Little stuff are the things that aren't that big, but you'd rather he didn't do. Distract his attention, move him to a new activity. Try not to say "no" all day.
Techniques. Try this one..At a quiet time make a list of the 5 specific behaviors for you would like to see improvement.Take them from most to least important.Take the 1st one and set consequences, such as a "good" time out.Explain this once to him.From then on, no further warnings but automatic time out for every infraction.Do not relent. 2-3 weeks and improvement occurs. Then go to #2 on your list, etc.Works!
Maybe. Without knowing the full situation here, including what discipline you've used, and what the acting out consists of, it's hard to say for sure, but it sounds like the relationship between you two isn't what either of you would want. Single parenting is never easy, and working with a therapist on your son's behavior and on how to cope with it and manage it may help turn things around.
3 yo behaviors. It depends what you mean by "acting out, " and it depends how you respond. I published and excellent book on kindle that could really help you. It is only $5.95 and is called: parenting the kids according to a child psychiatrist. I think, if you read my book, you will have a much easier time knowing how to handle your child's behavior. Good luck.