is he cheating?? help pls

When me and my boyfriend got together everything was fine, we was in love and I couldn't wish for anything better. After a few weeks he became distant, stopped calling me, wouldn't let me speak to him while he was at work, his battery kept on running out, choosing to spend nights with his friends instead of me, getting aggressive at me. Every time I pick up on something he becomes really defensive and blames me for my insecurity. One time I was at his house and his phone flashed up with a Facebook notification and as he opened it I seen him try and hide messages off other girls, he was asking them to meet because he was bored. Straight after he was so apologetic and he took me out to make up for it.... A few days after a girl from my high school contacted me on Facebook and sent me messages of him telling her that me and him are not together anymore, but once again i forgave him. Little things kept on happening and we were bickering, yesterday I was in college and another girl from my high school told me she met him in Feb ('as mates') and he told her we wasn't in a relationship, although we was. I went round to his house after college to find a viagra pill and one condom on his bedside table (we do not use this type of condom I found as I am allergic). So I questioned him and he said he was just cleaning out his draw, I believed him. I asked to go through his phone and he showed me that nothing was there so it made me feel better. Before I left his house he swore on his uncles life that he wouldn't cheat on me or hasn't cheated on me, I'm so confused and I don't know what to do... Am I too paranoid or is he really cheating on me??