Is there something wrong with my toddler :-(

I feel like my toddler hates me. All day he hits me, shouts at me, bites and hits himself whenever I deny him anything ..he is 2.7 months and always having crying fits and telling me to go away. I have a demanding three month old but I make as much time as I can for my toddler when baby is napping but even then instead of playing with me he throws stuff and tries to hurt me I don’t think this is normal , I try to stay calm and reassuring but sometimes i lose patience and i raise my voice/put him in time out. My postpartum depression doesn’t help but I cry myself to sleep every night because I feel like I have failed him and I dread every day 😣 does this sound normal or should I take him to his paediatrician, my husband thinks he has ADHD