the best advice i can give you is a piece i received many years ago and it really helps during the tough frustrating stretches of baseball season.
very simply, do not play any games when the line is more than a -150 lay.
that means steer clear of the game completely. no +185 dogs. no -210 favorites.
if you try to weather the storm playing games in the general 'pick'em' range or -130/+130 range, it does wonders for your psyche for a few reasons.
first of all, when you are cold, the last thing you want to do is lay MORE money to win a unit. during cold stretches, its hard enough to pick the straight up winner. theres no need to compound it with crazy juice.
now on the flip side, chasing with big dogs hoping for a quick score isnt the way to go either because big dogs often will fail to show profit short term. their benefit is long term. when things are going well, its easy to laugh it off when your +180 dog gets blasted 9-2. but during a cold stretch, it just leads to second guessing and regret.
for now, id say playing games that involve pick'ems and favs/dogs of up to 150 tops. maybe even 130 if you really want to be conservative while getting your confidence back.