Bubie- let me just start by saying "i know exactly how you feel "
My dd is 15months old and is exactly the same , she is very demanding and has been since she was a newborn , Everyone around me that has babies and children and even my own mother who has had two children cant get over how demanding she is at times .
by 5months old she would not let me out of her sight EVER , she would cry non stop if i left her with anyone at all until i came home and she would certinley not happily play on her own , i also had the same thing as you - if i was out at a friends place or at the mall she would not happily play on the floor or sit in her pram , she would need to be in my arms and even then she would quite often cry alot anyway , i found it so hard to take her anywhere , every trip to out seemed to involve a screaming fit and me running around stressed as trying figure out a way to keep her happy, it was such a smack in the face to see all the other mums have these perfectly well behaved happy babies and mine just seemed to cry and scream and never be satisfied, she was also a colic baby and woke 8-10times a night until she was 8months old .
it does get easier as they get older, the crying fits get fewer and preschool certinley helped for my dd, it took 2months of regular preschool visits with me right by her side and then me leaving for short periods of time ( an hour or two ) before i could leave her for an extended time ( i was back at work part time when she was 12months so preschool was a must ) . preschool has made her so much more independant , she happily plays on her own now , altho she is still extremley demanding at times she is alot easier to deal with .
also as others have mentioned about the sleep , my dd is a different baby when she hasent had her 12-14hours a night and 2-3hours a day , and thats at 15months old . my worst times with her was about 0-8months and that was when she was not sleeping well and hardly having day naps.
I also found the jolly jumper was fantastic , it gave me a few minutes to get things done and my dd loved it , she also had an exersaucer at 51/2mths and that kept her entertained too , she quite like to be upright and seeing me ( at home ) rather than lying on the floor .
How is your wee one at night time? does he sleep well ? I use to feed my dd to sleep because it was the only way she would go to sleep ( in my arms ) and she would wake so many times in the night because she didnt know how to self settle and she needed me to breastfeed her back to sleep .At 8months i did the sleep sense programme and it worked really well , it was very hard but i now have a 15month old who goes to sleep at 6pm and sleeps right through till anywhere between 7am-9am . if your having problems with him sleeping i have the programme and am happy to email it to you , just let me know 
All kids are so different and some of us just happen to get the children that are a bit harder work . i hope things improve for you soon .
Edited by julz85