What if I didn't get what I needed as a child?

I infer from your question a difficult childhood, perhaps abuse. Those first six to ten years are critical in that they form the basic neural-neural and neural-muscular synaptic connections that we carry with us. Changing them is possible and challenging. My wife was physically and emotionally abused as a child to the point where they “almost” put her in foster care. She learned early on that “everything was her fault.” When I married her at her age 24, knowing nothing of this, she was ‘tiny.’ 43 years later, she still says “I’m sorry” more than any other person I’ve met. We’ve worked hard with therapy and coaching on this so she’s much more outgoing, vivacious, and living “inside-out” rather that “outside-in” than she was then. And I was raised in an abusive alcoholic home so have had my own issues.

Here are some things that helped me/us.

1. Good therapists. Not all therapists are skilled. Find the ones that really help you.
2. Reading. My wife doesn’t read psychology, but I have a doctorate in human behavior in organizations (not clinical). Necessary Passages by Judith Viorst. Choice Therapy by William Glasser. I’m Ok, You’re Okay. They F*#k You Up by Oliver James. Love, Guilt and Reparation by Melanie Klein. A Guide to Rational Living by Albert Ellis. Adult Children of Alcoholics. Just for starters. It will be a lifelong issue. Even 1 or 2 books a year will help if you read them carefully.
3. Understand that you cannot change the past, but you can work to understand the “holes” you were left with and deal with them. The first one is to let go of or “divorce” your parents. Yes, it would have been better had we all had good and capable parents. We didn’t. When their lingering behavior and judgments no longer mean so much to you, their influence will begin to evaporate. It’s very difficult to divorce your parents. And it’s a necessary passage for those who were mistreated. I found my wife curled up in bed sobbing at age 33 because her mother in a phone call said she was “repulsive.” At some point to live a relatively normal life, one must divorce toxic parents.
4. Freud noted that we spend our adult lives dealing with the residue of our childhoods. Again, getting beyond that means no longer allowing those early “lessons” to dominate our lives and our self-esteems.
5. Reduce the power that the opinions of others have. Living “outside-in” is necessary for a functioning society, AND too much OI is unhealthy and creates doormats. Living above 50% “inside-out” means listening to others’ feedback as data but protecting your self-esteem. The gap between our IDEAL SELF (who we think we should be) and our SELF-IMAGE (who we think we are) affects our SELF-ESTEEM. BOTH IS and SI are affected by others. Don’t expect too much of yourself and don’t let others’ opinions especially your younger parents’ affect your SI overmuch. We live OI because we fear rejection. Examine that carefully. From whom? Why? Rejection by parents? God? Clergy? Friends? Nameless faceless people on the street?
6. Exercise creates good moods. Endorphins affect our mood positively. Exercise regularly. I took up non-contact “traditional” taekwondo at 52 and my self-confidence grew weekly. It’s a great system to build flexibility, strength, aerobic capacity, and mental toughness. Or walk briskly for 30′ a day.
7. Find a partner who loves you for who you ARE not whom they want you to be. That’s unconditional love. Most religions are built on conditional love—you have to do or be something else to be accepted. This just reinforces OI behavior.
8. Face your feelings. Stay away from anything that avoids dealing with your feelings. No drugs, alcohol, looking for love in promiscuity, tobacco. You will grow when you recognize and accept that you didn’t get what you needed when you were young and those evil substitutes won’t fill the hole.
9. Understand that brain chemistry plays a major role. Shadow Syndromes by John Ratey. Different brain chemistry issues can be alleviated with the right medications. My marriage was saved by ADHD medication for my wife.
10. Find a career you love. Create your purpose in life and pursue it. Don’t wait for others or God to tell you what to do. What do you want to spend YOUR life doing? Focus on that and do what you have to do to become really good at it. Let go of the VABE that a job is just a means to a small paycheck. Get out of the DO-REST-DO-REST cycle and into the DO-REST-LEARN-DO-REST-LEARN daily cycle.
11. Fight for your emotional and mental health. Don’t give up. It’s hard work. And it’s possible. If you fight for it.