Hi Tiggz so sorry to hear that you are having problems, but there is no reason to give up breast feeding unless you want to, and it is possible to mix feed for a while then go back to 100% breast.
A combination of very severe pnd and a very hungry baby meant we started supplementing at 3 weeks as my ds never seemed to be satisfied, however there was no problem with supply etc - he was just a very hungry baby - and some babies are.
I would caution though, as you have found out that it can be a bit of a slippery slope to ff as bf is a supply and demand system - the more you give ff, the less you will produce etc. And my ds at 5 weeks started to prefer the bottle and would fuss at the breast and refuse to feed because the bottle was easier.
It is possible to go back to full bf though - at one stage my son was having 60% ff and we gradually reduced the formula over a few weeks. Lots of skin to skin, shared baths and offering him the breast whenever, wherever.
We also kept him on the newborn teat size so he would have to work hard on the bottle as he would on the breast. When he got to about 9 weeks he started rejecting the bottle.
We persevered with the bottle for two weeks as my dh really wanted to carry on giving just one bottle at night as he enjoyed the bonding experience, while I could get some shut eye; but it became a battle of wills with my ds taking less and less and getting more distressed - he would start crying when he saw us with a bottle - from the other side of the room! As it was my son's choice we went back to full bf which we continued. I don't regret the ff at all, you do what's best for you and your baby in your own particular circumstances. I am very glad that he made the choice to go back to full bf -but would have been happy with my dh just doing one night feed too!
It would have helped if more people hsd reassured me that some babies just feed and feed and that's normal - most evenings ds would feed four hours at a stretch as he was using me as food and dummy and would fall asleep, then if you tried moving him, resume full time sucking.At 5 weeks we tried introducing a dummy but he never really took to them until much later.
I just gave up on the clock watching and decided to try and enjoy it as I had the luxury of no other children. I would pop him on to the nursing cushion (firm surface my brest friend) turn the tv on, and surf the internet with one hand. For hours.
If you have a hungry baby it is tempting to reach for the ff as you assume that your body is not producing enough milk or it's not satisfying enough. But if your getting enough wet and dirty nappies and they're putting on weight, then it's generally enough. Some babies are more hungry than others or less efficient feeders (my super efficient friend's baby has only ever fed for 5 mins at at time but is huge and on the 98th percentile).
The feeding forever stage doesn't last that long. It really does get better imo after 6 weeks, and a lot better after 12.