First of all, congratulations on your new baby!
I have a 4 mo and breastfed for the first 2 mo then gradually switched over to formula. I was really lucky with breastfeeding and ended up with a large supply. I was feeding baby on demand (which can be alot, sometimes every hour, sometimes every couple of hours - this is totally normal for new babies!) and also pumping twice a day to begin with too. If you would like to increase your supply I would suggest giving pumping a go, you can get a hand pump for relatively cheap to start with and then move on to an electric one if you want to continue - I used electric pumps as it was hands free, so easier, and much quicker at getting the milk. Only annoyance is having to wash and sterilise after each use.
In terms of the formula, I don't know how long you've tried each one for, but I would pick a standard one and stick to it for a few weeks. Just to give baby a chance to get used to it before you determine whether it might be beneficial to move on to a different type/brand. As I'm sure you know, all babies are different so there's no one size fits all :)
It's totally normal for babies to be colicky but if you're worried about constipation it's totally ok to speak to your HV or GP.
Also worth noting that sometimes the bottles your using can effect babies feeding too. I started using tommee tippee, but ended up switching to MAM. My lo had a tongue tie too which made it trickier, he was taking in so much air using the tt bottle so was very windy/colicky. After we switched to MAM we saw a massive improvement.
You are absolutely not failing your baby, newborns are hard and there isn't a manual. Be kind to yourself, you're doing a great job xx