Hi there - I posted a thread about the same topic a while ago so I can sympathise completely. I had exactly the same problem...and to be honest I just decided to leave it until he was older and I think it was the right decision...if you have that option.
I started trying with expressed milk when DS was about 6 weeks old. 1st few attempts were fine but then he took a strong dislike to the bottle so we decided to leave it.
Started trying again at 3 months with formula and he hated it - screaming the place down every time. The reason I was keen to do it was that I am going back to work in March so wanted DS to be used to the bottle for when he was at nursery. In the end I decided to give up as it was becoming too traumatic for us all and I hated to see DS so distressed.
So that I could be sure it was the bottle and not the formula itself that he didnt like, I tried feeding him formula off a spoon and he was happy to take that so I could be satisfied that the problem lay with the bottle.
HOWEVER, on Monday (DS now aged 5.5 months) I just thought I would try it and see and, hey presto, he took it no quibbles. He only had about 1.5 oz but it was a start...and he took the same amount again yesterday.
I think the turning point has been that I have started weaning him so he is getting used to having a spoon in his mouth and suddenly a bottle doesn't seem so alien. I had also started to give him a Tommee Tippee cup to play with so he had been chewing on the spout of that for a couple of weeks too.
Also, I used to always try in the evening and in hindsight he was tired and not in a very patient mood then. Perhaps I would have had more luck in the afternoon...
I was also advised on MN to use to the Tommee bottles as I had only used the Avent ones up til then - not sure if that has made a difference or not but I am not going to risk going back to the Avent ones now.
Best of luck - I know how stressful it can be, especially if you have a reason why you need to bottle feed. All you want is for your baby to have a good feed and to be satisfied by it, not upset.
If you are able I would just suggest taking your time and enjoy the BF while you can.