Pressuring Myself

I know that I am a person who often puts way too much pressure on herself.  Of course lately a lot of the self-inflicted pressure that I have been feeling has been relating to motherhood and taking care of our child. 
One of the main self-inflicted pressure items that I have been having issues with lately is the fact that I am an "old" mother.  I know in the technical sense of the word that I am not an "old" mother, and I am especially not an "old" mother in today's society.  Many women wait until they are in their 30s and 40s to have their first child nowadays.  You have to understand where I am coming from here, though...my Mom had me at 18 and had my sister at 25 and was done having kids.  My sister had her first child at 16 (she is currently 25) and her second at 24, and is now contemplating having a third.  All of this, along with comments from certain people, have compiled to make me feel like an "old" Mom for having my firstborn at 33.  And yes, we are planning on having at least one more, and yes, I have for some reason set a deadline of no more kids after 38 on myself to make matters worse.  I don't want to be having kids at 40.  No particular reason why, I just don't want to.
Another thing that I've been beating myself up about...this weekend we had to start introducing McKenna to formula.  I have been back at work for 4 weeks now, and of course now that I'm not able to nurse her most of the time, my supply has dropped off considerably.  Also, some of it is my fault, as I have been lazy and instead of nursing her in the evenings Justin and I have just been giving her expressed milk in a bottle.  She was taking 3 oz bottles at every feeding and just in the past week or so she has bumped up to 4 or 5 oz bottles at a feeding.  4 and 5 oz bottles with decreased milk production does not equal a successful way to feed our child.  We started giving her bottles with a 3:1 ratio of expressed milk to formula, or if she's been particularly hungry, a 3:2 ratio.  She has only been on the formula mixed with expressed milk for two days now, and seems to be OK with it.  I can't help sometimes thinking of other friends with children and being all like, "Hey, they were able to successfully nurse their kids for a year or more.  They also probably weren't lazy sluts like me and didn't nurse their children in the evenings and in the middle of the night when they woke up and needed a feeding."  Once again, no one is putting pressure on me but ME.  I think my friend Rachel said it the best to me the other day when we were talking about the aforementioned topic; she said, "I think that you need to do what's best for you and what works for you."  Thanks Rachel for the reality check.  Sometimes I need it. 
Until next time, I remain,
Jenuinely Yours